NAND array hiarchical BL structures for multiple-WL and All-BL simultaneous erase, erase-verify, program, program-verify, and read operations

ABSTRACT

Several 2D and 3D HiNAND flash memory arrays with 1-level or 2-level broken BL-hierarchical structures are provided for Multiple Whole-WL and All-BL simultaneous operations in Dispersed Blocks. The global bit line (GBL) is divided to multiple 1 (top)-level broken metal2 GBLs plus optional lower-level broken metal1 local bit lines (LBLs). A preferred V inhibit  supply higher than Vdd can be selectively supplied via horizontal metal0 power line LBLps to charge selected broken GBLs/LBLs which can also be selectively discharged via a String source line. Charge-sharing technique for precharging and discharging of broken GBL/LBL capacitors for NAND cell data sensing is used in Read and Verify operations with reduced power consumption and latency. Recall technique to restore the desired Program Data stored in the broken GBL/LBL capacitors is used for Multiple-WL and All-BL Program and Program-Verify operation with reduced program current for highest program yield superior P/E cycles.

1. CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 14/341,739, filed on Jul. 25, 2014 and claimspriority to U.S. Provisional Application No. 61/858,611, filed Jul. 25,2013, commonly assigned and incorporated by reference herein for allpurposes.

Additionally, this application is related to U.S. patent applicationSer. No. 14/316,936, filed Jun. 27, 2014, and U.S. patent applicationSer. No. 14/283,209, filed May 20, 2014, commonly assigned andincorporated by references herein for all purposes.

This application is also related to U.S. Patent Application No.2012/0051137 A1, U.S. Pat. No. 8,189,391, U.S. Pat. No. 8,169,826, U.S.Pat. No. 8,194,453, U.S. Pat. No. 8,203,882, U.S. Pat. No. 8,334,551,U.S. Pat. No. 8,148,763, U.S. Pat. No. 8,335,111, U.S. Pat. No.8,437,192, and U.S. Pat. No. 8,461,000, and U.S. Pat. No. 8,488,382 on3D NAND array architecture and operation.

2. BACKGROUND OF THE INVENTION

The present invention generally relates to advanced NAND memorytechnology. More specifically, the invention provides a repeatedlyelectrically erasable and programmable 2D or 3D NAND memory arraycomprising a unified multi-level hierarchical broken Bit Line (BL)structure that enables superfast and low-power Multiple Word Line (WL)and All-BL Simultaneous Erase, Erase-Verify, Program, Program-Verify andRead operations.

Conventionally, a 2D NAND flash includes several 2-dimentional (2D)planes on a common Triple P-well within a deep N-well on top of a commonsilicon P-substrate. When 2D NAND flash technology is scaled down below2×nm for increasing NAND memory size, it hits the wall to meet theMoore's scaling law, good data reliability and short latency. Thereliability issues include short data retention life cycle, highpower-consumption and low Program, Erase and Read cycles. The slowlatency issues include slow page-Read, page-Program,page-Program-verification, block-Erase and page-Erase-verification, etc.

The WL page size can be defined either in a large physical page sizesuch as whole WL or a smaller logic size such as ½ or ¼ of a wholephysical WL. The NAND's data storage types can be SLC, MLC, TLC, XLC oreven an analog one that stores more than 16 states per one physical NANDcell, regardless of 2D or 3D NAND memory.

Recently, many new 3D NAND flash memory cells and array architectureshave been proposed by using 3D transistors and Strings with acylindrical column type structures such as a multiple-layer stackedvertical-channel (VChl) 3D NAND technology from Toshiba, SanDisk andSamsung, or a vertical-gate (Vgat) NAND String technology from Samsung,and Macronix (Taiwan) and other 3D NAND flash technologies from Hynix,and Micron.

Although a 3D NAND flash memory has many advantages to use the lessadvanced technology nodes to increase NAND density over 1 Tb with asmaller silicon area than 2D NAND, it encounters new processdisadvantages such as high aspect ratio, stair-case etching etc, more WLdisturbance and new challenges to use the new scheme ofgate-induced-drain-leakage (GIDL) current to erase the 3D NAND flashcells, etc.

Irrespective of 2D or 3D NAND flash pros and cons under development,there are many common long-held old and new problems not beingcompletely solved and instead being mitigated when further scaling below2×nm. For example, the conventional 20-year good SBPI(Self-Boosting-Program-Inhibit) scheme has been found un-reliable inProgram and Program-Inhibit operations due to larger proximity couplingeffects such as the charging and discharging of adjacent BL-BL couplingnoises.

In other words, the conventional SBPI operations are strongly affectedby the stored Vts of two surrounding NAND cells dispersed in theadjacent left and right BLs. These coupling noise effects greatlydegrade the NAND data reliability and integrity, thus more errors andless P/E/R cycles are produced. As a result, more sophisticated ECCalgorithms are required to use those NAND memories made of more advancednodes below 3×nm.

As NAND density will be quickly exceeding 1 Tb with the circuit layoutscaled down to 10 nm or below, more power consumptions and latencies inRead, Program, and Erase operations are commonly found in product specs.It is desirable to improve NAND memory technology to solve the aboveproblems. The present invention provides a superfast, superior, andunified broken-BL hierarchical NAND array structure plus DRAM-like BLCharge-sharing and Sensing plus a novel Recall circuit aimed forimplementing Multiple-WL and All-BL simultaneous Erase, Erase-Verify,Program, Program-Verify, and Read operations on today's 2D and 3D NANDflash designs without cell and process changes, as described throughoutthe specification and all figures.

3. BRIEF SUMMARY OF THE INVENTION

This invention relates to advanced NAND memory technology. Morespecifically, the invention provides a 2D or 3D HiNAND memory arrayincluding a unified multi-level hierarchical broken-Bit-Line (BL)structure configured to be repeatedly electrically erasable andprogrammable for enabling superfast and low-power Multiple Word Line(WL) and All-BL Simultaneous Erase, Erase-verify, Program,Program-verify, and Read operations. Due to very broad aspects of thecombinational architectures of HiNAND arrays of the present invention,the following summary cannot include all key features of the inventions.Thus the summary below should not be treated as a limitation of thepresent invention. One of skilled in the field should recognize manyvariations and alternatives within the scope of claims herein.

When HiNAND array uses only one preferred tight 2λ vertical metal1 for a1-level BL array scheme, then it is referred as HiNAND1. When HiNANDarray uses two preferred vertical tight 2λ metal1 and 2λ or 4λ metal2lines if odd/even GBL scheme is used for a 2-level BL architecture, thenit is referred as HiNAND2. Accordingly, when HiNAND array uses onevertical tight 2λ metal1, but less tight metal2 and metal3 for a 3-levelBL architecture, then it is referred as HiNAND3. All above HiNAND2 orHiNAND1 arrays use a horizontal metal0 for connecting the common sourcenodes of a plurality of NAND Strings and V_(inhibit) power supply lines.HiNAND3 has been filed by the same inventors of this application, thusthe details are skipped here.

For description simplicity, the term of “Multiple-WL and All-GBLsimultaneous Operations” is simply used to represent “Multiple-WL andAll-GBL simultaneous Erase, Erase-Verify, Program, Program-verify andRead Operations” for the subsequent description below.

The first objective of the present invention is to propose a 1-levelbroken metal1 global bit line (GBL) hierarchical structure for a HiNAND1array to perform the preferred Multiple-WL and All-GBL simultaneousoperations. The HiNAND1 array includes J NAND Groups with J−1Group-divided transistors MGBL extending from array top to bottom in GBLor Y-direction, connected by one broken-GBL metal1 line associated witha broken parasitic capacitor C_(GBL). Each HiNAND1 Group is furtherdivided by L Segments in series with L−1 Segment-divided NMOStransistors of MDBLp and each Segment is comprised of K identical NANDBlocks, with layout extending in Y-direction. Lastly, each NAND Block isfurther comprised of N identical NAND Strings cascaded in WL orX-direction. J, L, K, and N are integers. Each NAND-String includes M 2DNMOS NAND cells in series with one top String-select transistor MS andone bottom String-select transistor MG. The value of M can be 8, 16, 32,64, 128 or any arbitrary integer number. In this application, one Stringincludes 64 WLs or NAND cells as an example. Each physical NAND cell canstore 2-state SLC, 4-state MLC, 8-state TLC or 16-state XLC or even256-state analog values.

In an embodiment, the length of each metal1 GBL line extending oneHiNAND1 Group is the longest metal1 line unit for charge-sharingsimultaneous Multiple-WL Read operation of the HiNAND1 array. Thereby,this metal1 line is preferably referred as a broken Group metal1 line.Additionally, each broken Group metal1 line per Group can be furtherdivided into L smaller broken Segment metal1 lines by L−1Segment-divided NMOS transistors of MDBLp. Thus, the length of brokenSegment metal1 line associated with one Segment is 1/L of each brokenGroup metal1 line. The broken Segment metal1 line is located at a samelevel topologically as the broken Group metal1 line.

In another embodiment, the length of each broken Segment metal1 lineextending one HiNAND1 Segment is the shortest metal1 line unit forsimultaneous Multiple-WL Program operation of HiNAND1 array.

The second objective of the present invention is to propose a 2-levelbroken GBL/LBL hierarchical structure for a HiNAND2 array to performpreferred Multiple-WL and All-GBL simultaneous operations. Like HiNAND1array, the HiNAND2 array includes of similar J NAND Groups in series,extending from array top to bottom in BL or Y-direction, connected byone broken Group metal2 GBL line associated with a parasitic capacitorC_(GBL). Note, the length of each broken Group metal2 GBL line extendingone HiNAND2 Group without being further broken like the HiNAND1 Groupmentioned before is the longest metal2 line for charge-sharingsimultaneous Multiple-WL Read operation of HiNAND2 array. But eachbroken Group metal2 GBL line at top level is further connected inparallel to L metal1 LBL lines located at bottom level. Each metal1 LBLline is associated with one Segment in one Group of the HiNAND2 array.Each Group includes L Segments. Thus, the length of each metal1 LBL lineis about 1/L of each broken Group metal2 GBL line. Alternatively, eachmetal1 LBL line can be further divided to n metal1 broken-LBL lines,each of them can be the shortest metal1 line for simultaneousMultiple-WL Program operation of the HiNAND2 array. In other words, eachSegment is divided into n sub-Segments and each sub-Segment includes Kidentical NAND Blocks extended in Y-direction. Each Block is furthercomprised of N identical NAND Strings cascaded in WL or X-direction.Each NAND String includes M NMOS NAND cells in series with one topString-select transistor MS and one bottom String-select transistor MG.J, L, n, K, M, and N are integers. Preferably, J=8 or 16, L=4, n≧4, Kdepends on memory density, M=64, and N=65,536 for 8 KB page. Again, eachphysical NAND cell, a 2D cell in this embodiment, can also similarlystore 2-state SLC, 4-state MLC, 8-state TLC or 16-state XLC or even256-state analog values.

The third objective is to propose a NMOS 1-poly MHV transistor MGBL,same type as typical NAND String-select transistors MS and MG, fordividing a large metal1 GBL line for the HiNAND1 array to J broken Groupmetal1 lines and similarly a NMOS 1-poly MHV transistor MDBLp forfurther dividing each broken Group metal1 lines to L smaller brokenSegment metal1 lines. Alternatively, for the HiNAND2 array with 2-levelBL hierarchical structure, it is to propose a similar MGBL transistorfor dividing a large metal2 GBL line to J metal2 broken-GBL lines(capacitors) respectively associated to J Groups. Each metal2 broken-GBLline in a Group located at a top level is connected via L MLBLptransistors respectively to L smaller metal1 LBL lines located at bottomlevel and respectively extended over one of L Segments within the Group.It is proposed to have n−1 MDBLp transistors, similar to those used inHiNAND1 array, for dividing each smaller metal1 LBL line (or capacitor)of a Segment to n broken-LBL metal1 lines respectively associated with nsub-Segments Blocks. Each sub-Segment contains K Blocks, where J, L, K,n can be any integer number and J is preferred to be 8 and 16. As aresult, this preferred 2-level broken-BL HiNAND2 array, regardless of 2Dor 3D configuration, is comprised of J Groups with J×L Segments andJ×L×n×K Blocks in Y-direction. Again, each Block is further comprised ofN identical NAND Strings cascaded in WL or X-direction. Additionally,one or more metal0 power lines GBLps and Vss lines CSL are laid out inX-direction for the HiNAND1 array and several power lines LBLps and Vsslines CSL are also laid out in X-direction for the HiNAND2 array.

The fourth objective of present invention is to propose that one end ofeach metal1 broken GBL line (capacitor) of HiNAND1 array is preferablyconnected to one corresponding horizontal metal0 power line, GBLps,through a 1-poly NMOS MLBLs transistor (same type of transistor like MSand MG transistors). In other words, one metal0 GBLps line is associatedwith one Segment per each Group in the HiNAND1 array. Each common metal0GBLps line has two purposes. The first purpose is used as a power supplyline for the HiNAND1 array in initial precharge operation on allselected broken Group/Segment metal1 lines to charge the correspondingbroken GBL capacitors up to V_(inhibit) voltage during Multiple-WL andAll-BL operations. In contrast, the second purpose is used as a Vss lineto discharge each selected Segment and Group lines or capacitors.

The fifth objective of present invention is to propose that one end ofeach bottom-level metal1 LBL line (or capacitor) of a Segment in theHiNAND2 array is preferably connected to one corresponding common metal0power line, LBLps, per Segment through a NMOS 1-poly transistor MLBLs(like String-select transistors MS and MG). The other end of eachbottom-level metal1 LBL line of the Segment is preferably connected toone top-level metal2 broken GBL line through a MHV NMOS transistorMLBLp. All the smaller metal1 LBL lines associated with L Segments inthe Group are connected in parallel to each corresponding larger metal2broken GBL line (or capacitor). The metal1 LBL line of the Segment canbe further divided into n broken-LBL metal1 lines by n−1 transistorsMDBLp, each metal1 broken-LBL line belonging to a sub-Segment associatedwith a broken-LBL capacitor. One metal0 line LBLps connects commonly toeach broken-LBL metal1 line respectively via a transistor MLBLs in theHiNAND2 array. Firstly, the LBLps line is used as a power supply linefor the HiNAND2 array in initial precharge operation to charge allselected metal1 broken-LBL lines up to V_(inhibit) voltage at the LBLcapacitors during the Multiple-WL and All-BL operations. Secondly, theLBLps line is used as the Vss line to discharge each selected brokenSegment and Group lines (or capacitors).

The sixth objective of present invention is to propose that eachtop-level metal2 broken-GBL line in HiNAND2 or broken Group metal1 linein HiNAND1 array is a N-bit BL flexibly connected to either 1-sidedN-bit Page Buffer (PB) circuit or 2-sided N-bit PB circuit for an evenlypower-saving distribution and faster speed performance for the preferredMultiple-WL and All-GBL simultaneous operations.

In an embodiment, the bit number of the PB can be made same as N-bitGBLs in one physical WL. In this scheme, the one physical N-bit pagedata trapped in the corresponding broken Group N-bit GBL capacitor orbroken Segment N-bit LBL capacitor from a N-bit PB just needs 1-cycle of1-page loading either from the top-side PB or the bottom-side PB of theHiNAND array.

In another embodiment, the bit number of either 2-sided or 1-sided PBcan be made of N/2-bits, which is only one-half of N-bit of GBLs in onephysical WL. In this scheme, the whole one physical N-bit WL's datatrapped in the corresponding broken Group N-bit GBL capacitors from aN/2-bit PB needs 2-cycle of half-page data loadings so that wholeMultiple Full-WL, All-BL Program and Erase can still be performed eitherfrom the top-side PB or the bottom-side PB.

The seventh objective of present invention is to propose that eachtop-level metal2 N-bit broken-GBL lines (capacitors) in a HiNAND2 arrayand the metal1 broken-GBL lines (capacitors) in a HiNAND1 array ispreferably divided into two equal halves with a N-bit PB preferablybeing placed in the middle of either the HiNAND2 or the HiNAND1 arraywith two sets of N-bit outputs. The first set of N-bit outputs connectupward to the first N-bit GBL of top half of the HiNAND2 array and thesecond set of N-bit outputs connect downward to the second N-Bit GBL ofbottom half of the HiNAND2 array. In this scheme both top and bottomhalf of HiNAND2 arrays can be performed the Multiple Whole-WL and All-BLProgram, Program-Verify, and Read operation simultaneously in 1-cycle.

The eighth objective of the present invention is to propose a preferredmethod to determine an optimal number J of all broken GBL lines orcapacitors per column of a HiNAND1 array. The optimal number of J ismainly determined by the latency and reliable charge-sharing operationsof Read and Program-Verify operations rather than by Program operation.

For a Multiple-WL and All-GBL Read and Program-Verify operations, thenumber of broken GBLs is determined by a preferred ratio R(HiNAND) ofthe farthest, relative to a 1-sided N-bit PB, Jth broken GBL capacitanceto the sum of total J GBL capacitances when all the J−1 dividedtransistors MGBLs are turned on the same time to allow the N-bit sensedAll-GBL data voltages to pass from the Jth GBL capacitor to the N-bit PBthrough J−1 GBL capacitors for N-bit data simultaneous evaluation. Thepreferred ratio R(HiNAND) equals to 1×C_(GBL)/J×C_(GBL)=1/J, where10≦J≦20. The value of J below 10 is better for charge-sharing DRAM-likeSA but at the expense of larger overhead with increasing number of MGBLtransistors. Note, R(HiNAND)=R(DRAM), which is defined as a ratio ofeach DRAM cell capacitance to each DRAM BL capacitance and typicallyless than 1/20. Regardless of the HiNAND2 and HiNAND1 arrays, thepreferred values of J are J=8 or 16.

The ninth objective of the present invention is to propose a preferredmethod to determine an optimal number L of all metal1 LBL lines (orcapacitors) per HiNAND2 Group. The optimal number L is determined by thepower-consumption of the preferred Program-Inhibit scheme by precharginga V_(inhibit) voltage on the selected N-bit metal1 LBL capacitors withinthe selected Segments of a Group in the HiNAND2 array for less powerconsumption in Read and Program-Verify operations. In a specificembodiment, the preferred value of L is determined by an equation J/L=4per four Segments for each metal2 broken-GBL line or capacitor for apreferred Multiple Whole-WL and All-GBL Read and Verify operations. Inother words, each top level metal2 broken-GBL line of a Group isconnected in parallel to four bottom-level metal1 LBL lines associatedwith 4 Segments. Each metal1 LBL line of a Segment is preferably dividedinto n≧4 metal1 broken LBL lines respectively associated with n sets ofK Blocks for precharging to V_(inhibit) voltage on the selected smallerN-bit metal1 broken-LBL capacitors within the selected Segments of aGroup in the HiNAND2 array for less Program power consumption. EachBlock includes N identical NAND Strings cascaded in WL or X-direction.The preferred length of each metal1 broken LBL line is the length of K2D HiNAND cell Strings in Y-direction (where n typically is 4 and K isany integer depended on area density of the flash memory chip).

The 10th objective of the present invention is to propose a preferred nbottom-level broken-LBL metal1 lines per each NAND Segment, eachbroken-LBL metal1 line being associated with a parasitic line capacitor,C_(LBL). There are two preferred ways to form this broken-LBL metal1line. In a first embodiment, each Group associated with a broken-GBLmetal2 line overlaps with L Segments and each Segment includes L smallerLBL metal1 lines in the HiNAND2 array. Each Segment is divided into nsub-Segment. In other words, the total number, m, of broken-LBL metal1lines per GBL column (Y-direction) per Group is m=L×n, where eachsub-Segment has a broken-LBL metal1 line. Each broken-LBL metal1 lineconnects in parallel to K HiNAND Strings in Y-direction. Note, theHiNAND String is the same as conventional NAND String in terms of Stringlength in this application. But only one top C_(LBL) capacitor of the nbroken-LBL metal1 lines or capacitors per Segment is preferablyconnected to the top-level metal2 broken-GBL line through a MHV 1-polyNMOS transistor MLBLp with its gate being tied to a control signal, suchas SEG_1 [1], . . . , or SEG_1[L], in each selected Group J,respectively. In addition, only one bottom C_(LBL) capacitor of the nbroken-LBL metal1 lines per Segment is preferably connected to a bottommetal0 line LBLps_1[L] laid in X-direction through a MHV 1-poly NMOStransistor MLBLs with its gate being tied to one signal, such asPRE_1_n[1], . . . , or PRE_1_n[1:L], in each selected Group J,respectively. In an alternative embodiment, the number of LBLps linescan be increased n times to have one LBLps line per K Blocks.

The 11 th objective is to use a NMOS MHV voltage device as the one usedas String-select transistor MS (or MG) in conventional NAND for each ofMDBLp and MLBLs transistors for forming broken GBLs or broken LBLs inthe preferred HiNAND1 and HiNAND2 arrays of the present invention. OtherHV device meeting BVDS spec higher than MHV MS and MG can also be used.

The 12th objective is to have a flexibility to divide each broken-GBL orbroken-LBL lines in equal and unequal lengths and capacitances in all 2Dand 3D HiNAND arrays. In an embodiment, the length of those farthest GBLor LBL lines (or capacitors) relative to a page buffer (PB) at one endof the HiNAND array are preferably made much larger than those in aGroup nearest to the PB for a less dilution of charge-sharing voltagesfor superior DRAM-like sensing scheme used in the HiNAND array. Forexample, the length of farthest Segment or Group BL line can be made 4×longer than the nearest Segment BL line in each Group or nearest GroupBL line relative to the PB.

The 13th objective of the present invention is to differentiate J Groupswith different Read latencies and power-consumption in an one-sidedN-bit or N/2-bit PB of the HiNAND2 and HiNAND1 array. Because the Group1 is the nearest Group to the top-sided PB, it is a HiNAND Group withthe fastest operation and the least power-consumption. The Group J isfarthest Group from the top-sided PB, thus it is termed as a HiNANDGroup with the slowest operation and the highest power-consumption. Forexample, for reading Operation System code programs, it requires leastRead latency upon power-up cycle so that its data are preferred to bestored in the Group 1.

The 14th objective of the present invention is to differentiate J Groupswith different Read latencies and power-consumption in a 2-sided N-bitor N/2-bit PB HiNAND2 and HiNAND1 array. The Group 1 and Group J arenearest to the top PB and bottom PB respectively, thus both Group 1 andGroup J are termed as the fastest NAND Group with the leastpower-consumption. The middle Group(s), Group J/2 and Group J/2+1, arethe farthest Groups from both top and bottom PBs, thus they are termedas the slowest NAND Groups with the highest power-consumption. Forexample, for reading Operation System code programs, it requires leastRead latency upon power-up cycle so that its data are preferred to bestored in the Group 1 and Group J.

The 15th objective of the present invention is to precharge anddischarge each selected metal2 broken-GBL line and each correspondingmetal1 broken-LBL line through the one pair of transistors MLBLp andMLBLs so that no extra power-line like LBLps_J is required for eachmetal2 broken GBL capacitor in HiNAND2 array to save layout area. Forfully passing the V_(inhibit) voltage from a selected metal0 line LBLpsto each metal1 LBL capacitor, the gate voltages of MLBLs transistors,PRE_1_1[1]==PRE_1_1˜n[L], are applied with V_(inhibit)+Vt+V_(margin),where V_(margin)≧0.5V and control signal SEG_1[1] is applied with Vss todisconnect each metal2 broken GBL line from the corresponding metal1broken LBL line.

The 16th objective of the present invention is to disclose a preferredRead, Program, and Program-Inhibit schemes for HiNAND array to savepower consumption and to perform faster Multiple-WL and All-BLsimultaneous Program operation. This simultaneous Multiple-WL and All-BLProgram operation can be successfully implemented by precharging allselected N-bit metal1 broken LBL lines first with a V_(inhibit) voltage(up to about 7V) from only one selected metal0 LBLps line and thendischarging part of the N-bit metal1 broken LBL lines selectively basedon the data “zero” sent by the PB from selected metal2 broken GBL linesthrough the corresponding MLBLp transistors. The precharged V_(inhibit)voltage would be retained in the remaining part of the N-bit LBL linesif the corresponding data from the PB are “one.”

After the completion of discharge/non-discharge operation of first N-bitmetal1 LBL capacitors of a first page data, the Program andProgram-Inhibit page data is then locked therein. The Multiple-WLProgram and Program-Inhibit data would be repeatedly locked in ortrapped in the remaining selected N-bit metal1 LBL capacitors. Once allthe selected WL Program and Program-Inhibit data being successfullystored in the corresponding pages of N-bit metal1 BL capacitors, then aset of Vpgm (15V to 25V) and Vpass (10V) for one selected and 63non-selected WLs per String would be applied to all selected Blocks forsimultaneous Multiple-WL Program (assuming each Block comprising of 64NAND cells connected in series with two String-select transistors of MSand MG).

The 17th objective of the present invention is to disclose a preferredMultiple Whole-WL and All-BL simultaneous Read operation. Thissimultaneous Read operation can be successfully implemented byprecharging all the selected N-bit metal1 LBL capacitors in HiNAND2array first with a V_(inhibit) voltage of Vdd reversely from only oneselected LBLps line through a MLBLs transistor to each selected N-bitLBL line, and then through the divided transistor MDBLp (turned on)along the path of metal1 LBL line to reach the broken LBL capacitor andthen through the corresponding NMOS MHV MLBLp transistor to the selectedmetal2 broken-GBL capacitor. Thus the conventional N-bit all-GBLprecharged Vdd voltages are not from the N-bit PB through the long andheavy unbroken metal2 GBL line. Instead, the Read precharged voltage isdirectly coupled from only one selected metal0 power line LBLps inX-direction to the N-bit smaller metal1 LBL lines (capacitors) forachieving dramatic power reduction.

Afterwards, the precharged V_(inhibit)=Vdd on the N-bit metal1 LBLcapacitors will be selectively discharged to 0V by the stored “1” datain the multiple selected WLs in the multiple selected Blocks in themultiple selected Segments of one or more selected Groups.

This simultaneous Multiple whole-WL and All-GBL Read operation can bestarted after the completion of trappings of V_(inhibit) voltage on allmultiple selected metal1 LBL lines (capacitors). The finalnon-discharged V_(inhibit) voltage in all N-bit LBL capacitors inmultiple Blocks would be dumped to the corresponding broken GBLcapacitors in a predefined order for a DRAM-like charge-sharing Readscheme. A preferred charge-sharing Sense Amplifier (SA) operation can bedone with an analog voltage reduced from the V_(inhibit) voltage whichis then amplified by a Multiplier and sent to DRAM latch-type SA forfinal N-bit data simultaneous evaluation. The preferred order ofcharge-sharing operation and SA data evaluation for each broken GBLcapacitor is started from the top Group 1 which is the nearest to thePB. After the Group 1 is read into the PB, the broken-GBL capacitorvoltage in Group 1 has to be reset to Vss and ready for the next GBLcharges from Group 2 with the voltage diluted by half before being fedto the Multiplier. Accordingly, the Jth GBL capacitor's V_(inhibit)voltage would be dumped into the longest GBL line with 1/16 V_(inhibit)dilution before fed to the Multiplier and then SA for final dataevaluation.

The 18th objective of the present invention is to disclose two preferredsets of the 64-WL biased Program and Program-Inhibit (PI) voltages alongwith the preferred V_(inhibit) voltages on each LBL capacitor for aHiNAND array that is comprised of a plurality of 64-cell NAND Strings ineach NAND Block. These two preferred PI schemes includes a) using SBPIscheme with V_(inhibit)=Vdd and V_(program)=Vss for the HiNAND Programoperation, and b) using non-SBPI scheme with V_(inhibit)>Vdd andV_(program)=Vss for the HiNAND Program operation. Note: SBPI stands forSelf-Boosting-Program-Inhibit.

The 19th objective of the present invention is to disclose a preferredDispersed Block architecture for the 2D HiNAND array as oppose to theconventional Consolidated Block scheme for 2D NAND. In this preferredDispersed 2D HiNAND Block, one or more dispersed WLs of K WLs can beflexibly selected for simultaneous Erase operation with the same Eraseconditions such as TPW=20V, with the selected V_(WL)=0V andV_(SSL)=V_(GSL) at floating to reduce the selected cells' Vt=Vte≦−0.7V.A preferred set of Erase biased conditions for this HiNAND array such asSSL and GSL lines and SEG lines, PRE lines, DI lines and DIV_EN lineswill be shown. The values of K=16, 32, 64, 128 or any integer number. Inan embodiment, the Erase operation of the 2D HiNAND flash cell uses aFN-channel tunneling scheme.

The 20th objective of the present invention is to disclose a preferredDispersed Block architecture for a 3D HiNAND array as oppose to theconventional Consolidated Block scheme for 3D NAND. In this preferredDispersed 3D HiNAND Block, similarly, one or more dispersed WLs of K WLscan be flexibly selected for simultaneous Erase operation with the sameErase conditions to reduce the selected cells' Vt=Vte≦−0.7V. The valuesof K=16, 32, 64 or any integer number. But the Erase operation of the 3DHiNAND flash cell uses preferred GIDL hot-hole injection scheme to raisethe 3D flash cell channel's polysilicon bulk potential against 0V WLvoltage to tunnel the stored electrons in a 3D flash cellcharge-trapping layer for its Vt reduction.

The 21th objective of the present invention is to disclose a preferredset of biased voltage conditions for multiple selected WLs, the multipleremaining unselected WLs, and the multiple selected and unselected SSLand GSL lines and SEG lines, PRE lines, DI lines and DIV_EN lines forthis Multiple Whole-WL and All-GBL simultaneous Erase-Verify operationof the preferred HiNAND array.

The 22th objective of the present invention is to disclose two preferredErase schemes that will be used in 3D HiNAND array. The first Erasescheme is like the traditional 2D NAND that applies 20V in NAND's bulkTPW to perform reverse FN-channel Erase to remove the electrons in thefloating-gate to reduce the NAND's Vt. The second Erase scheme is to useeither top or bottom or both 3D select transistors in a 3D HiNAND Stringin the 3D HiNAND array to generate a high GILD hole current to increasethe selected flash bulk voltage to a level such as V_(erase)=20V toremove electrons in the charge-trapping layer.

The 23th objective of the present invention is to disclose both abovepreferred Erase schemes plus the preferred decoding circuits, one WL ormore than one WL or whole WLs Erase and Erase-Verify operations can beflexibly and simultaneously performed in both Consolidated and DispersedBlocks of 2D and 3D HiNAND arrays.

The 24th objective of the present invention is to disclose a preferrednew Block decoder with an additional Latch circuit to have the flexibleSet and Reset functions to allow independently and randomly selectingone or more Block decoders for the preferred Multiple-WL and All-GBLsimultaneous operations for both 2D and 3D HiNAND arrays.

The 25th objective of the present invention is to disclose a preferrednew circuit of Broken GBL and LBL decoders to allow independently andrandomly selecting one or more rows of the broken-GBL transistor MGBLand the broken-LBL transistor MDBLp. In order to have a full passage ofvoltages up to 7V in GBL and LBL, the GBL and LBL drives need to outputa HV on the control signals of DIV-EN and DI_1.

The 26th objective of the present invention is to disclose a preferrednew circuit of LBLps line to supply the following voltages to metal1 LBLcapacitor: a) LBLps=V_(inhibit) for LBL's Program-Inhibit voltage, whereVdd≦V_(inhibit)≦7V; b) LBLps=V_(inhibit) for LBL's Read, Erase-Verify,and Program-Verify precharged voltage, where V_(inhibit)=Vdd; c)LBLps=Vss for discharging the LBL capacitors or the corresponding GBLcapacitors.

The 27th objective of the present invention is to disclose a preferredset of voltages for one selected WL and multiple unselected WLs alongwith a preferred set of Vss and V_(inhibit) for all BLs in the selectedBlocks so that a random multiple-WL and All-BL simultaneous Program andProgram-Verify operations can be achieved for both HiNAND1 and HiNAND2arrays.

The 28th objective of the present invention is to disclose a flow schemeand circuit for performing a preferred Multiple Whole-WL and All-GBLsimultaneous Read operation. The operation requires only one N-bit CachePB for a N-bit SLC Read, two N-bit Cache PB for a 2×N-bit MLC Read,three N-bit Cache PB for a 3×N-bit TLC Read, and four N-bit Cache PB fora 4×N-bit XLC Read by using a new scheme of “Recall” along with the oneor more levels broken-BL hierarchical structure that inherently has manyexisting pages of available N-bit LBL capacitors to temporarily storeK×N-bit page-data (regardless of SLC, MLC, TLC and XLC) of multipleselected WLs without overheads of the extra data registers.

The 29th objective of the present invention is to disclose a techniqueto use existing free multiple N-bit pages of Sample-and-Hold (S&H) LBLcapacitors as Dynamic Cache to temporarily store the multiple-WL pagedata (in Segments of a Group) near the N-bit PB, rather than to store inmultiple pages of real Cache Registers as used in conventional NAND, tosave silicon area. The total numbers of rows or pages of N-bit S&Hcircuit depend on types of storages data. Typically one row of N-bit S&HLBL capacitors for N-bit SLC storage data, while two rows of N-bit S&Hcircuit for N-bit MLC storage data, three rows of N-bit S&H circuit forN-bit TLC storage data and lastly four rows of N-bit S&H circuit is forN-bit XLC storage data.

The 30th objective of the present invention is to disclose a preferredRotation capacitor assignment with n rotation Dynamic Cache Registersand one Dynamic PB per multiple-state storage data in the HiNAND array.The value of n is subject to the NAND storage type. For example, forSLC, n=1, MLC, n=2, TLC, n=3 and XLC n=4. One N-bit Dynamic CacheRegister is to store N-bit one-WL Program pattern, while one N-bitDynamic PB is to store one-WL N-bit Program and Program-Inhibit pattern.The Rotation capacitor assignment is based on one Group size of n+1N-bit LBL capacitors or n+1 WLs for one Dynamic PB and n Dynamic CacheRegisters in the HiNAND array. During the progression of Multiple-WLProgram, the selected WL is shifted or rotated from first WL to thefinal WL. Thus the only one Dynamic PB for each selected WL has to beshifted inside n+1 WLs. The details will be explained in accordance withFIG. 4A and FIG. 4B of this application.

The 31th objective of the present invention is to disclose a novelRecall function, which is defined as a DRAM-like page-based Readoperation to allow the sensing of 1-page program voltage data stored inone designated page of Dynamic Cache Register by a PB located at top orbottom of the HiNAND array during this preferred Program-Verifyoperation. The Recall operation is performed directly to read the Nstored voltages in accordance with the program page data loaded fromI/O, as oppose to the program-verify that reads cell's stored analog Vtfrom the selected WLs. The required number of Dynamic Cache Registersfor this broken-BL hierarchical HiNAND array is determined by thestorage types. For SLC, only 1 Dynamic Cache Register is required, whilefor MLC, 2 Dynamic Cache Registers are required, TLC needs 3 DynamicCache Registers and XLC needs 4 Dynamic Cache Registers.

This preferred Recall operation is performed through using a first stepof a DRAM-like Charge-sharing (CS) Read between one accessed C_(SEG)with up to J×C_(GBL) (assuming the array is divided into J brokenGroups), then performing a second step of a Multiplier's analog voltageamplification and lastly a third step of a Latch-type SA's full digitalamplification to recall the previously stored 1-page program data backto Static-PB in one read cycle of the present invention.

For a proper Read of two distinct diluted voltage data pattern such as,Vdd/J vs 0V or V_(inhibit)/J vs. 0V after CS, the ratio of 1/J value ispreferred set to be not smaller 1/16 as adopted by a DRAM Read.

The 32th objective of the present invention is to disclose severalpreferred PI (Program-Inhibit) schemes for this HiNAND array, regardlessof 2D or 3D technologies. The key difference between HiNAND Program andNAND Program is that each N-bit Page data of V_(inhibit) and Vss of eachWL data are not directly controlled remotely by the N-bit PB througheach long GBL as in conventional NAND dealing with one WL Program only,instead, in the HiNAND with Multiple whole-WL and All-GBL Programscheme, the multiple page data in V_(inhibit)/Vss patterns of theselected multiple WLs are allowed to be latched or stored in multiplesteps in selected metal1 LBL capacitors in the selected Segments andGroups. Thus the simultaneous multiple whole-WL and All-BL Programoperation becomes feasible without causing any data contention in theshared N-bit PB.

The 33th objective of the present invention is to disclose severalpreferred PI (Program-Inhibit) schemes for this HiNAND array, regardlessof 2D or 3D technologies. The key differences between HiNAND Program andNAND Program are summarized below:

-   -   a) V_(inhibit) voltage≧7V is a much higher initial voltage in        selected HiNAND cell's channel voltage V_(chl) than Vdd used in        the conventional NAND cell supplied from a N-bit PB.    -   b) Vpass=10V to obtain the highest V_(chl) before Program is        initiated.    -   c) Multiple randomly WLs are selected for concurrent Program        from multiple dispersed Blocks on a basis of one-WL per one        Block, each of the multiple dispersed Blocks belonging to        different sub-Segment associated with a broken-LBL capacitor,        each sub-Segment being selected randomly to same or different        Segments of the same or different Groups.        This is termed as Multiple random-WL Program in the Dispersed        NAND Blocks. A higher PI's V_(inhibit) voltage is used by HiNAND        array in the beginning of the page Program.

The 34th objective of the present invention discloses that all the abovementioned objectives, techniques, broken-BL hierarchical structures in2D HiNAND flash array can be similarly applied in various 3D NAND arraysand technologies for the preferred Multiple-WL and All-GBL simultaneousProgram, Read, Erase-Verify, and Program-Verify operations. Theconventional 3D NAND technologies include 1) The vertical-channel 3DNAND technologies from Toshiba's BiCS and PiCS Vertical-channel NAND,Samsung's TCAT, and Hynix's DC-SF; 2) The vertical-gate 3D NANDtechnology from Samsung, Macronix, etc. In 2D HiNAND architecture, theoptimal length of capacitance of each broken metal1 LBL line isoptimally set around four 2D HiNAND Strings for the tradeoff between theoverhead of added MLBLps MHV devices and PI precharge-current. But in 3DHiNAND flash architecture, the length of each LBL line of four or more3D NAND Strings takes less area, thus less capacitance. As a result, itshould be increased to more than 8 Strings to increase corresponding 3Dbroken LBL capacitance. Similarly, each broken GBL capacitance isreduced due to the 3D HiNAND Strings takes less area.

The 35th objective of the present invention is to disclose all aboveproposed 2-level broken BL HiNAND2 array can be reduced to 1-levelbroken BL HiNAND1 array only with metal1 broken GBL lines for differentand high-density memories such as NOR array, SARAM array, DRAM array,PLD array, CAM array, and ROM array. This 1-level divided GBLarchitecture with segmented DGBL capacitance would result in faster readspeed. For those cells read from the selected divided GBL capacitancenear SA would have the highest read speed. For those cells located inthe other end of column farthest away from SA would have the slowestread speed. The MGBL device used for dividing each long GBL line can bemade of LV NMOS device in DRAM, SARAM and CAM and PLD designs with alarger channel width to reduce the pass resistance for not affecting theread BL delay.

4. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-sectional view of a 2D NAND memory cell with channelbiased condition at MV=V_(inhibit) for Program-Inhibit (PI) according toan embodiment of the present invention.

FIG. 1B is a cross-sectional view of a 2D NAND memory cell with channelbiased condition at Vss=0V for Program according to an embodiment of thepresent invention.

FIG. 1C is a diagram of 3-bit 8-Vt distribution of TLC-type storage forNAND memory cell according to an embodiment of the present invention.

FIG. 1D is a cross-sectional view of a memory unit device configurationof a conventional U-shape vertical-channel 3D memory String thatcomprises eight 3D NAND cells.

FIG. 1E shows respective side cross-sectional view and topcross-sectional view of two optional device configurations of analternative conventional vertical-channel 3D NAND memory String.

FIG. 2A is a circuit diagram of a 2D HiNAND1 array including 1-levelhierarchical broken-GBL structure for multiple-WL and All-GBLsimultaneous Erase, Erase-verify, Program, Program-Verify, and Readoperations according to a specific embodiment of the present invention.

FIG. 2B is a circuit diagram of a 2D HiNAND2 array including 2-levelbroken-BL hierarchical structure for multiple-WL and All-GBLsimultaneous Erase, Erase-Verify, Program, Program-Verify, and Readoperations according to another specific embodiment of the presentinvention.

FIG. 3 is a block diagram of a Page Buffer circuit for both the HiNAND2and HiNAND1 arrays according to embodiments of the present invention.

FIG. 4A is a simplified circuit diagram of a HiNAND2 array of FIG. 2Bperforming Sample & Hold functions of a Multiple-WL TLC Programoperation according to a specific embodiment of the present invention.The HiNAND array has been divided into 8 Groups. Each Group large metal2GBL capacitor (or GBL line) is divided into 8 Clusters of 4-Segmentmetal1 capacitors through 8 divided GBL transistor of MLBLp. EachGroup-broken metal2 line has eight 4-Segment metal1 capacitors connectedin parallel. Each 4-Segment cluster includes one Segment being assignedto be one Dynamic Page Buffer (PB) and three Segments being assigned tobe Dynamic Cache Registers. The assignments are preferably rotated amongthese 4 Segments. FIG. 4A shows that the first Segment of Cluster 1 inthe dispersed eight Groups is assigned to be one Dynamic PB but the nextthree Segments are assigned to be three corresponding Dynamic CacheRegisters for storing one corresponding 3-bit TLC data.

FIG. 4B is a simplified circuit diagram of a HiNAND2 array of FIG. 2Bperforming Sample & Hold functions of a Multiple-WL TLC Programoperation according to another specific embodiment of the presentinvention. The assignment of 4-Segment metal1 capacitors are rotatedwith the last Segment of Cluster 8 in the dispersed eight Groups beingassigned to one Dynamic PB and the first three Segments being assignedto be three corresponding Dynamic Cache Registers for storing anotherone corresponding 3-TLC data.

FIG. 4C is a simplified circuit diagram of a HiNAND2 array of FIG. 2Bperforming Sample & Hold functions of a Multiple-WL TLC Programoperation according to another specific embodiment of the presentinvention. The assignment of 4-Segment metal1 capacitors are rotatedwith the first Segment of all eight Clusters in Group 1 being assignedto one Dynamic PB and the next three Segments in each Cluster beingassigned to be three corresponding Dynamic Cache Registers for storinganother one corresponding 3-TLC data.

FIG. 4D is a simplified circuit diagram of a HiNAND2 array of FIG. 2Bperforming Sample & Hold functions of a Multiple-WL TLC Programoperation according to another specific embodiment of the presentinvention. The assignment of 4-Segment metal1 capacitors are rotatedwith the first Segment of all eight Clusters in Group 8 being assignedto one Dynamic PB and the next three Segments in each Cluster beingassigned to be three corresponding Dynamic Cache Registers for storinganother one corresponding 3-TLC data.

FIG. 5A is a circuit diagram of 1-bit static PB circuit that comprisesone Multiplier circuit, one 1-bit Sense Amplifier circuit and one 1-bitSLC Data Register, along with one Y-pass circuit, One Cache Register,one I/O Control and multiple I/O [1:X] pins for Multiple-WL and All-GBLSimultaneous SLC operations for both HiNAND1 and HiNAND2 arraysaccording to an embodiment of the present invention.

FIG. 5B is a circuit diagram of multi-bit static PB circuit for HiNANDarray that allows to store e-bit NAND multiple-state page data forMultiple-WL and All-BL Simultaneous (MLC, TLC, XLC, . . . ) operationsaccording to an embodiment of the present invention.

FIG. 6A is a diagram showing a set of SLC Read timing waveforms forMultiple-WL and All-GBL simultaneous Read operation with a preferred setof initial biased conditions in accordance with the 1-bit static PBcircuit shown in FIG. 5A of both HiNAND1 and HiNAND2 arrays according toan embodiment of the present invention.

FIG. 6B is a diagram showing a set of Sample/Hold Multiple-WL SLC PGMpatterns timing waveforms in accordance with the 1-bit static PB circuitshown in FIG. 5A of both HiNAND1 and HiNAND2 arrays according to anembodiment of the present invention.

FIG. 6C is a diagram showing a set of set biased conditions ofMultiple-WL and All-GBL SLC simultaneous PGM timing waveforms inaccordance with the 1-bit static PB circuit shown in FIG. 5A.

FIG. 6D is a flow chart showing a method for the preferred Multiple-WLand All-GBL SLC simultaneous Program operation in accordance with thepreferred PB circuit shown in FIG. 5A.

FIG. 7A is a diagram showing a set of MLC Read timing waveforms forperforming the preferred Multiple-WL and All-GBL MLC simultaneous Readoperation in accordance with the multi-bit static PB circuit shown inFIG. 5B of both HiNAND1 and HiNAND2 arrays according to an embodiment ofthe present invention.

FIG. 7B is a diagram showing a set of Sample/Hold Multiple-WL PGMpatterns timing waveforms for the preferred Multiple-WL and All-GBL MLCsimultaneous Program Patterns operation in accordance with the multi-bitstatic PB circuit shown in FIG. 5B.

FIG. 7C is a diagram showing a set of biased conditions of Multiple-WLand All-GBL MLC simultaneous PGM timing waveforms in accordance with thepreferred PB circuit shown in FIG. 5B.

FIG. 7D is a flow chart showing a method for the preferred Multiple-WLand All-GBL MLC simultaneous Program operation in accordance with themulti-bit static PB circuit shown in FIG. 5B.

FIG. 8 is a diagram showing a preferred set of bias voltage conditionsof array control signals for Multiple-WL & All-GBL simultaneous Readoperation based on the HiNAND1 array shown in FIG. 2A according to aspecific embodiment of the present invention.

FIG. 9 is a diagram showing a preferred set of bias voltage conditionsof array control signals for Multiple-WL & All-GBL simultaneous Readoperation based on the HiNAND2 array shown in FIG. 2B according to aspecific embodiment of the present invention.

FIG. 10 is a diagram showing a first preferred set of bias voltageconditions of array control signals for Multiple-WL & All-GBLsimultaneous Program operation based on the HiNAND1 array shown in FIG.2A according to a specific embodiment of the present invention.

FIG. 11 is a diagram showing a second preferred set of bias voltageconditions of array control signals for Multiple-WL & All-GBLsimultaneous Program operation based on the HiNAND1 array shown in FIG.2A according to a specific embodiment of the present invention.

FIG. 12 is a diagram showing a first preferred set of bias voltageconditions of array control signals for Multiple-WL & All-GBLsimultaneous Program operation based on the 2D HiNAND2 array shown inFIG. 2B, regardless of SLC, MLC, TLC and XLC storages, according toanother specific embodiment of the present invention.

FIG. 13 is a diagram showing a second preferred set of bias voltageconditions of array control signals for Multiple-WL & All-GBLSimultaneous Program operation based on the 2D HiNAND2 array shown inFIG. 2B, regardless of SLC, MLC, TLC and XLC storages, according to yetanother specific embodiment of the present invention.

FIG. 14 is a diagram showing a preferred set of bias voltage conditionsof 2D or 3D HiNAND2 array for a preferred Multiple-WL & All-GBLsimultaneous Erase operation using Channel-Erase scheme, regardless ofSLC, MLC, TLC and XLC storages, according to an alternative embodimentof the present invention.

FIG. 15 is a diagram showing a preferred set of bias voltage conditionsof 2D or 3D HiNAND2 array for a preferred Multiple-WL & All-GBLsimultaneous Erase operation using GIDL Erase scheme, regardless of SLC,MLC, TLC and XLC storages, according to another alternative specificembodiment of the present invention.

FIG. 16 is a simplified circuit diagram showing a 3D HiNAND2 array with2-transistor divided-GBL/LBL device and U-shaped vertical-channel Stringaccording to an embodiment of the present invention.

FIG. 17 is a simplified circuit diagram showing a 3D HiNAND2 array with3-transistor divided-GBL/LBL device and U-shaped vertical-channel Stringaccording to another embodiment of the present invention.

FIG. 18 is a simplified circuit diagram showing a 3D HiNAND2 array with1-transistor divided-GBL/LBL device and with U-shaped vertical-channelString according to yet another embodiment of the present invention.

FIG. 19 is a simplified circuit diagram showing a 3D HiNAND2 array with1-transistor divided-GBL/LBL device and with straight vertical-channelString according to still another embodiment of the present invention.

FIG. 20 is a simplified circuit diagram showing a 3D HiNAND2 arraycompatible with vertical-gate NAND cell string scheme according to aspecific embodiment of the present invention.

FIG. 21 is a diagram showing six decoding logics for eight layers of thevertical String selected-transistors of the 3D vertical-gate HiNAND2array structure of FIG. 20 according to a specific embodiment of thepresent invention.

The above diagrams are merely examples, which should not unduly limitthe scope of the claims herein. One of ordinary skill in the art wouldrecognize many other variations, modifications, and alternatives. It isalso understood that the examples and embodiments described herein arefor illustrative purposes only and that various modifications or changesin light thereof will be suggested to persons skilled in the art and areto be included within the spirit and purview of this process and scopeof the appended claims. Note, all above 3D HiNAND2 arrays have 2-sidedSense Amplifier (SA) and multiple-level hierarchical BL structures. Allof them can be turned into 3D HINAND2 with 1-sided SA and multiple-levelbroken-BL hierarchical structures so that the preferred concurrentcharge-sharing, precharge, and discharge in Read and Verify operationscan be performed with faster speed and less-power consumption.

5. DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description of the present invention,reference is made towards the accompanying drawings, flow charts,diagrams, and tables that form a part hereof and in which is shown, byway of illustration, specific embodiments in which the invention may bepracticed. In the drawings, like numbers describe substantially similarcomponents throughout the several views and embodiments. Theseembodiments are described in sufficient detail with a goal to enablethose skilled in the art to practice the invention. Other embodimentsmay be made without departing from the scope of the present invention.Additionally, the following detailed description is not to be taken in alimiting sense, and the scope of the present invention is defined onlyby the appended claims and equivalents thereof. In other instances,well-known structures and devices are shown in block diagram form,rather than in detail, in order to avoid obscuring the presentinvention.

Please note, if used, the labels left, right, top, bottom, middle,higher or lower level X or Y-direction, column or row direction,horizontal or vertical direction both in drawings or mentioned indescription, have been used for convenience purposes only and are notintended to imply any particular fixed direction. Numerical denotationusing J, L, K, M, N, m, n, is also for convenience purpose andcorresponding examples of these numbers, such as 1, 2, 3, 8, 16, 32, 64,256, etc are not intended to limit the scope of the present inventiondefined by the appended claims. Instead, they are used to reflectrelative locations and/or directions between various portions of acircuit object or schematic diagram.

Unlike prior-art 2D NAND has only one 1-level unbroken and tight 2λmetal1 global bit line (GBL) architecture extending vertically (or incolumn direction, or Y-direction) a long way from each array top tobottom with a heavy BL capacitance along with a plurality of horizontalmetal0 Vss lines, in general, embodiments of the present inventionprovide a HiNAND array preferably including 1-level or 2-levelhierarchical structure with broken and tight 2λ meal2/metal1 GBLs andtight metal1 local bit lines (LBLs) along with a plurality of horizontalmetal0 Vss and power lines. Throughout this specification, a NAND arraywith 1-level broken metal1 GBL is termed as HiNAND1 array, while a NANDarray with 2-level broken metal2 GBL and broken metal1 LBL is termed asHiNAND2 array (compared with the conventional NAND array with 1-levelunbroken and tight 2λ metal1 GBL).

The length of each metal2 or same metal1 GBL is formed to be much longerthan the length of each metal1 LBL line in HiNAND array so that theDRAM-like Charge-sharing sensing scheme for the preferred Multiple-WLand All-BL Simultaneous operations can be reliably realized with lowpower consumption and low latency.

For the preferred Multiple-WL and All-GBL simultaneous Programoperation, a precharged V_(inhibit) voltage on all selected, smaller,broken metal1 LBLs in HiNAND2 array or a broken metal1 GBL line inHiNAND1 array is required for power saving. The V_(inhibit) voltage ispreferably set to be larger than Vdd for HiNAND array and is generatedfrom a V_(inhibit) pump circuit and is then coupled to the selected LBLand GBL capacitors through a selected horizontal metal0 GBLps line inHiNAND1 or metal0 horizontal LBLps line in HiNAND2 array. The prechargecurrent will be too high when the precharged voltage is greater than Vddand GBL and LBL capacitance are also too large. And that is why a brokensmaller LBL or broken GBL line is required for lowering the prechargecurrent for charging to V_(inhibit) in this preferred Multiple-WL andAll-GBL simultaneous Program operation based on HiNAND arrays.

Conversely, for the preferred Multiple-WL and All-GBL simultaneous Readand all Verify operations such as Program-Verify or Erase-Verify, aprecharged V_(inhibit) voltage or Vdd voltage on all selected largebroken metal1 GBL lines in HiNAND1 array or a large broken metal2 GBLline in HiNAND2 array is required for a fast, reliable DRAM-like BLCharge-sharing sensing scheme implemented in this preferred HiNANDarray.

Besides multiple-level broken-BL hierarchical structures, some othernovel circuits or techniques such as Recall and Sensing, Dynamic CacheRegisters and Dynamic PB formed inside 2D HiNAND array to store theprogrammed data patterns will be disclosed and explained throughout thisspecification. In addition, all above mentioned multiple-level broken-BLhierarchical structures, operating schemes and biased conditions for the2D HiNAND array circuits can be extended into the 3D HiNAND arraycircuits with a super fast, lower-power Program and Read operations.

FIG. 1A shows a cross-sectional view of one 2-poly, NMOS, 2D NAND cellsubjected to a preferred non-SBPI's program-inhibit bias conditionaccording to an embodiment of the present invention. As shown, the cell,referred as the 2-poly HiNAND cell in this invention, is formed insidethe TPW 27, within the DNW 28 on top of P-substrate 29, structurally thesame as conventional NAND cell. In an alternative embodiment, the 2DHiNAND cell can also be a 1-poly MONOS cell using a charge-trappinglayer made from Nitride for data storage. In another alternativeembodiment, this HiNAND cell can be made of either 2-poly floating-gatetransistor with poly1 layer 20 on top of poly2 layer 22 separated by athin oxide layer 21. Poly2 layer is separated from the channel byanother thin oxide layer 23 in between. Further, the cell can also bemade of a 1-poly charge-trapping layer NMOS transistor (not shown).

FIG. 1A shows that the 2-poly HiNAND cell is subjected to a biased(charged) voltage of MV in both drain node 26 and source node 24 forProgram-Inhibit. In particular, the gate 19 is applied with word lineVpgm voltage a while the MV at cell channel is at program-inhibitV_(inhibit) voltage which is greater than Vdd, for exampleV_(inhibit)=7V. One advantage of adopting HiNAND broken-BL hierarchicalstructure is to allow the easiest setup of a low-power, least WL-passdisturbance, using multiple schemes for Program and Program-Inhibitoperations including the enhanced SBPI (ESBPI) and direct non-SBPI aswell as the conventional SBPI scheme to achieve high-yield and superiorprogramming of 2D and 3D NAND flash memory.

Conventionally, more than 7V is generated in channels of thenon-selected NAND cells through the coupling effect of rising WL-gate20V with an initial floating Vdd-Vt voltage, which is about 1V whenVdd=1.8V. But when adopting HiNAND architecture, this 7V or greater canbe generated directly from a V_(inhibit) pump circuit and then directlycoupled to the channels of unselected programmed NAND cells in multipleselected WLs and pages simultaneously by using the preferred low-powernon-SBPI scheme as disclosed in the present invention. With V_(inhibit)voltage being directly supplied to the channels of non-selected NANDcells, thus this non-SBPI V_(inhibit) method is very effective with highProgram and Program-Inhibit (PI) yield.

In an embodiment, a low-power ESBPI scheme is adopted to use a biasvoltage more than Vdd but preferably below V_(inhibit) of 7V. SinceESBPI uses V_(inhibit) higher than Vdd as used by conventional NAND,thus, the PI yield should be much higher and more reliable. Again usingthe ESBPI method, the bias voltage is also preferably generated from apump on chip that is not coupled from the PB on top of NAND array. Thusthe HiNAND architecture based on these HiNAND cells can still use thelow-voltage PB as prior-art NAND design. Since the charged bias voltageis less than 7V, thus coupling effect similar to SBPI is still required.

Besides above two preferred PI methods, the third SBPI scheme using Vddas program-inhibit voltage like the prior-art NAND can still be used forthe present 2D HiNAND architecture for Multiple-WL and All-GBLsimultaneous Program operation. Note, all above three methods, the SBeffect to increase non-selected NAND cell channel voltage from therising WL is still valid.

For those program-inhibit HiNAND cells, the channels are coupleddirectly with V_(inhibit) from a V_(inhibit) pump circuit through apreferred metal0 LBLps in HiNAND2 array or from a metal0 GBLps line fromHiNAND1 array, rather from PB. The Vt of Program-Inhibit cells would notbe increased. If the Vt is E-state, then the program-inhibit cell's Vtshould remain at E-state. Similarly, when A-state, B-state and C-statecells get program-inhibited, then they should stay at their respectiveinitial A-state, B-state and C-state without being increased to nexthigher states.

In an embodiment, FIG. 1A shows the Non-SBPI biased conditionsassociated with the HiNAND cell: gate node Vg (19)=Vpgm=15V-25V, sourcenode Vs (24) and drain node Vd (26) are at MV=V_(inhibit)˜7V (Note,V_(inhibit) is directly supplied by a selected LBLps or GBLps lines).V_(TPW) (27)=0V, V_(DNW) (28)=Vdd, and Vp-sub (29)=0V. In anotherembodiment, FIG. 1A also shows the ESBPI biased conditions: gate node Vg(19)=Vpgm=15V-25V, source node Vs (24) and drain node Vd(26)=V_(inhibit), Vdd<V_(inhibit)<7V (Note, V_(inhibit) is directlysupplied by a selected LBLps or GBLps lines). V_(TPW) (27)=0V, V_(DNW)(28)=Vdd, and Vp-sub (29)=0V.

FIG. 1B shows a preferred set of program bias conditions of 2D HiNANDcell for one or multiple-WL Program operations in 2D NAND flash cell.Again, the cell structure and device physics are the same for 2D HiNANDcell or 2D NAND cell and is also kept the same for 3D cell, too, inRead, Program, Erase, Program-Inhibit conditions without any process anddesign changes. After a low-power FN-channel Program operation thattakes about 250 μS per SLC, 2D HiNAND cell's programmed Vts is increasedfrom its initial negative erased-state (E-state) of Vte (≦−0.7V) tothree desired positive programmed states such as A, B, C for a MLC cellor 7 positive states for one TLC cell and 15 positive states for one XLCcell.

As shown in FIG. 1B, the following Program bias conditions associatedwith the 2D HiNAND cell: gate node Vg (19)=Vpgm=15V-25V, source node Vs(24) and drain node Vd (26) are at 0V, V_(TPW) (27)=0V, V_(DNW)(28)=Vdd, and Vp-sub (29)=0V. Based on the conventional NAND cell butwith new concept of broken global or local bit lines hierarchicalstructure, the HiNAND array architecture is provided in the presentinvention for achieving many advantages in power reduction, reducedlatency, and increased speed in Program and Read operations.

FIG. 1C shows an exemplary eight Vt distributions of one TLC 2D or 3DHiNAND cell with 8 binary state assignments of 111, 110, 101, 100, 011,010, 001 and 000 for 3 bits of one TLC data denoted as D3, D2 and D1.The E-state is termed as LSB state, H-state is the MSB state, andA-state to G-state are termed as 6 CSB states of one TLC cell. The eightstates from LSB to MSB include E, A, B, C, D, F, G and H states fromleft to right. Many other eight TLC state assignments can also beaccepted for both 2D and 3D HiNAND cell and array.

As shown, there are 7 verification voltages such as VFY1 to VFY7 as aregular 2D and 3D NAND with 7 corresponding Read voltages such as R1 toR7 for one selected WL in prior-art NAND's one-WL Program scheme but formultiple selected WLs for HiNAND's multiple-WL novel Program scheme.There are plenty of different VFYn and V_(Rn) setups for multiple-stateVt for one 2D or 3D NAND cells of prior-art NAND. All these prior-artsingle-WL VFYn and V_(Rn) setups can be adopted by HiNAND but extendedinto multiple-WL VFYns and V_(Rn)s with the same biased conditions onthe same row address in all selected 64 WLs either in one consolidatedBlock or 64 dispersed WLs in 64 dispersed Blocks of HiNAND array. For aSLC storage, only 2 states of E-state and A-state are used with n=1, 2,while a MLC storage, 4 states of E, A, B and C are used. Similarly, for15 states of XLC of larger assignments is used for both 2D and 3DHiNAND.

In today's 2D NAND spec, a SLC program time is about 250 μs, a MLCprogram time is about twice of SLC, a TLC program time is about 3× ofSLC of 750 μs, and is 1.75 ms for a TLC Program, referred to N-bit cellsfor respective SLC, MLC, TLC, or XLC. In one-WL page Program, theprogram sequence starts from the bottom N-bit 2D NAND cells of WL[64]next to a top String-select transistor MG to the top N-bit 2D NAND cellWL[1] next to a bottom String-select transistor of MS per WL at a time.

More detailed six steps of one-WL Program in conventional 64-cell Stringof a 2D NAND is summarized below:

1st-step: Loading programmed-data cycle. The desired maximum programdata in unit of one single physical WL of page with N GBLs are loadedinto multiple N-bit Dynamic PBs and NX multiple Dynamic page buffers,serially or in parallel. The Program operation is then either performedin two ways: a) 1-cycle All-BL page Program scheme; b) 2-cycle of ½-BLOdd and Even logic pages Program scheme.

2nd-step: All 64 WL voltages of one selected Block pre-setting cycle.All gate lines of 64 selected WLs and two String-select transistors inone selected NAND Block are preset to the 1^(st)-stage of the desiredbiased voltage such as Vpass of 10V with V_(SSL)=Vdd (bottomstring-select transistor MS's gate) and V_(GSL)=Vss (top String-selecttransistor MG's gate) to avoid BL leakage in one selected NAND Block.

3rd-step: GBL V_(inhibit) and Vss Precharging cycle of one selected WL.All N-bit GBL lines are coupled to the desired V_(inhibit) and Vss inone selected WL in accordance with the desired page data stored in eachPB at top of NAND array prior to Program operation.

4th-step: Single-WL simultaneous Program cycle. Only one selected WL inthe selected Block is then coupled to a ramping voltage of Vpgm(15V-25V) for one iterative program pulse with a width ranging from 10μs to 20 μs. The remaining 63 unselected WLs voltage are kept unchangedat Vpass of 10V. Different PI methods such as SB, LSB and EASB are usedfor Program. There are many un-selected Vpass voltages proposed by manyprior-art NANDs. These different Vpass voltages include Vpass1, Vpass2to VpassJ. The voltages of Vpass1 to VpassJ vary from as low as Vss toVdd to Vpass.

5th-step: Single page or WL Program verification cycle. All N-bit GBLcapacitors are precharged to Vdd-Vt from top N-bit PB for 1-cycleAll-GBL Read or 2-cycle ½-GBL Read. The precharged voltage of Vdd-Vt ineach metal1 GBL is V_(GBL)=Vdd-Vt=0.7V to 1.0V. In this cycle, a slowand high pre-charged GBL current happens. A check of N-bit or ½N-bitdata comparison is performed between the desired WL programmed datastored in the static-PG from system with the programmed data read outfrom one selected WL. If data comparison is matched, then Program isended. If fails, then the Program and Program-Verify iteration arecontinued to the preset loops.

6th-step: Repeat single-WL Program and Program-Verify operation untilthe program time spec is over. The iterative single-WL Program andProgram-Verify are performed only when the programmed data fails to meetthe desired stored data in PB. The data can be SLC, MLC, TLC, and XLC oreven the analog data with more than 16 Vt states per cell.

The present invention provides embodiments one- or multiple-WL andAll-BL simultaneous Program operations for 2D HiNAND array, where thenumber of steps and the function of each step are different from aboveseries of steps. Details will be found throughout this specification andparticularly in subsequent paragraphs in accordance with FIG. 2A andFIG. 2B.

FIG. 1D is a cross-sectional view of memory unit device configuration ofa conventional U-shape vertical-channel 3D memory String that compriseseight 3D NAND cells. As shown, one U-shape 3D NAND 8-cell String isconfigured with one separate drain-string-select transistor 81 and onesource-string-select transistor 82 respectively coupled at two ends.Layer 51 is a Vss metal0 line running in row direction of memory arrayand layer 52 is a metal1 bit line (BL), running in column direction andperpendicular to the metal0 Vss line. This 3D NAND String is formed onU-shaped body 74 with eight cells, such as 71 d, 71 a, etc including agate insulation layer 73 being stacked in stacking direction.Additionally, a back-gate transistor 61 with same gate materialincluding back-gate hole 62 is formed on the same body 74B(74) at thebottom of the stack. The blocking insulation layer 73 a, charge-trappinglayer 73 b, and tunnel insulation layer 73 c are shared by all 8 celltransistors and the back-gate transistor 61. But the drain and sourceNMOS string-select transistors 81 and 82 are respectively using thenon-charge-trapping layers 87 and 88 with gate insulation layer 85 and86 in between. The drain and source side holes 83 and 84 are formedrespectively to penetrate the gates 81 and 82. The non-charge-trappinglayer 87 of the drain-string-select transistor 81 is connected to themetal1 layer 51 via another metal layer 55 in the stack direction. Thedetailed description of the memory unit device can be referred to avertical-channel 3D NAND scheme shown in U.S. Pat. No. 8,169,826 B2,titled with “Nonvolatile Semiconductor memory Device”, and incorporatedfully for references.

Throughout the disclosure of the specification, it will be seen that apreferred HiNAND array architecture with broken GBL or LBL scheme can beapplied to convert the above U-shape vertical-channel 3D NAND structuresto a 3D HiNAND structure for many advancements in Multiple-WL and All-BLProgram, Read, and Program-Verify operations. The number of 3D NANDcells in a String can be flexibly extended from 8 cells shown in FIG. 1Dto 16, 32 or even 64 for more area reduction.

Similarly, other known vertical 3D NAND structures can also be turnedinto a 3D HiNAND1 or HiNAND2 broken-BL array structure for Multiple-WLand All-BL operations. The same techniques disclosed here in thisapplication can be also applied to different configurations ofalternative 3D NAND structures. For example, FIG. 1E shows respectiveside cross-sectional view and top cross-sectional view of twoconventional device configurations of an alternative vertical-channel 3Dmemory String. As shown in right side of the figure, an option2configuration for a conventional 3D vertical NAND string is formed onsubstrate 100 with a lower electrode 102 below channel 1 and an upperelectrode 202 over the channel 1 having a pillar shape perpendicular tothe substrate 100. A plurality of control gate electrodes 3 formed overa stack of multiple device levels around the pillar shaped channel 1. Ablocking dielectric 7, having a C-shape in the side cross-sectionalview, is located adjacent to and surrounded by the control gateelectrodes 3. A plurality of discrete charge-trapping segments 9 isrespectively disposed in the opening portion of the C-shaped blockingdielectric 7 and coupled around the channel 1 via a surrounding tunneldielectric 11. For the option 1 configuration shown in left side of thefigure, the channel 1 is hollow inside which is filled with aninsulation fill material 2. The top cross-sectional view reveals clearlythe relative positions of the channel 1 (as well as fill material 2),the tunnel dielectric 11, the charge-trapped segments 9, and theblocking dielectric 7. The upper electrode 202 is the equivalent localmetal1 line laid out to connect each vertical-channel 3D NAND String andthe lower electrode 102 is connected to metal0 CSL line. The details ofthe vertical-channel 3D NAND cell technology shown above can be referredto U.S. Pat. No. 8,461,000, titled with “Method of Making UltrahighDensity Vertical NAND Memory Device”, incorporated fully as references.Based on the above 3D NAND cell String configuration by introducing ascheme with broken metal2 GBL, a broken metal1 LBL, metal0 for CSL, andmetal0 LBLps line, a novel 3D HiNAND broken-BL hierarchical structurecan be easily made for performing preferred Multiple-WL and All-GBLsimultaneous Erase, Erase-Verify, Program, Program-Verify, and Readoperations according to embodiments of the present invention. Details ofthe 2D (and 3D) HiNAND broken-BL hierarchical structure can be foundthroughout the specification and particularly below.

FIG. 2A is a circuit diagram of a 2D HiNAND1 array including 1-levelbroken-BL hierarchical structure for multiple-WL and All-GBLsimultaneous Erase, Erase-verify, Program, Program-Verify, and Readoperations according to a specific embodiment of the present invention.As shown, the 2D HiNAND1 array has 1-level broken-BL metal1 lines andone 2-sided page buffer (PB). In an embodiment, the 2D HiNAND1 arraypreferably comprises J HiNAND1 Groups, such as Group 1 to Group J,arranged in column (or Y) direction of a 2D matrix of NAND cells. The Jbroken-metal1 BL lines form J capacitors C_(GBL) in series divided byJ−1 NMOS transistors, MGBL, where J is an integer selected from 8, 16,or greater. In other words, between any two adjacent C_(GBL) capacitorsof two adjacent Groups, there exists one bridge NMOS MHV device of MGBLtransistor to connect two adjacent divided metal1 C_(GBL) lines orcapacitors. For total J HiNAND1 Groups, there are total J−1 dividedM_(GBL) transistors but J broken-GBL divided capacitors such as C_(GBL)_(_) ₁ to C_(GBL) _(_) _(J-1) per one column of the 2D HiNAND1 array.

Each HiNAND1 Group is further divided into L Segments in Y-direction(column direction) by L−1 Segment-select transistors, MDBLp, connectedby shorter metal1 line within. The L Segments include Segment 1 toSegment L from top to bottom connected by L shorter broken metal1 lines(local capacitors such as CGBL_1_1 to CGBL_1_L) in each Segment.Furthermore, each HiNAND Segment is preferably divided further into KBlocks connected by K shorter metal1 lines in series in columndirection. Each HiNAND1 Block further comprises N-bit NAND Strings thatare cascaded in X-direction (row direction). Each HiNAND1 Stringcomprises m NAND cells in series and sandwiched by one top and onebottom String-select transistors, MS and MG, respectively, where m=8,16, 32, 64, 128 or any selected integer.

In addition, one end of each bit line for each Segment is connected to acorresponding metal0 power line, GBLps, along the X-direction through acorresponding NMOS transistor, MLBLs. This GBLps line is used for eitherprecharging the local broken metal1 shorter Segment GBL line with avoltage up to V_(inhibit) as explained above but also used fordischarging it to Vss after program.

From top static-PB (Page-Buffer) viewpoint, all J HiNAND1 Groups with JC_(GBL) capacitors are connected in series from the top Group 1capacitor C_(GBL1) directly and then through J−1 M_(GBL) bridgetransistors and J−1 metal1 C_(GBL) capacitors to reach the bottom andlast C_(GBLJ) capacitor. From circuit viewpoint, the top static-PB ofHiNAND1 array would have the smallest RC loading because only one1×C_(GBL) capacitor but zero resistance when reading the top Group 1 WLdata without a need going through one transistor resistor MGBL at allwith all with J−1 transistors MGBL being shut off in non-conductionstate by setting control signals DIV_EN[1]= . . . =DIV_EN[J−1]=Vssduring the Group 1 Read and Program operations. In contrast, in HiNAND1array, the largest RC loading on each broken GBL line of each bit ofstatic-PB when one WL is read out from Group J, which suffers thehighest capacitances of J×C_(GBL) capacitors and J−1 resistances of J−1MGBL transistors by setting control signals DIV_EN[1]= . . .=DIV_EN[J−1]≧Vdd+Vt+ΔV_(margin) to fully turn on the J−1 MGBLtransistors to allow full-passage of BL voltage among L Segments of JGroups.

The precharge and discharge of each C_(GBL) capacitor can still berealized by connecting each broken C_(GBL) line (corresponding to eachSegment) to each corresponding metal0 power line LBLps through eachcorresponding divided BL transistor MLBLp by setting control signalsSEG_1 [1]= . . . =SEG_1[L]=Vdd or a higher Vread voltage.

In summary, HiNAND1 array is a circuit with 1-level broken Group andSegment GBL hierarchical structure. Although there only one metal1 lineused to divide each long GBL line into broken ones for Groups andSegments, the preferred multiple-WL and All-GBL simultaneous Erase,Erase-Verify, Program, Program-Verify, and Read operations can beperformed in either Consolidated or Dispersed Blocks for SLC, MLC, TLC,and XLC storages. More details about these operations would be explainedthroughout the specification and particularly in several paragraphsbelow in accordance with a 2-level broken-BL hierarchical HiNAND2 arraycircuit shown in FIG. 2B.

FIG. 2B is a circuit diagram of a 2D HiNAND2 array including 2-levelbroken-BL hierarchical structure for multiple-WL and All-GBLsimultaneous Erase, Erase-Verify, Program, Program-Verify, and Readoperations according to another specific embodiment of the presentinvention. This diagram is merely an example, which should not undulylimit the scope of the claims herein. One of ordinary skill in the artwould recognize many other variations, modifications, and alternatives.As shown, FIG. 2B is a specific embodiment of HiNAND2 array circuit witha 2-level broken-BL hierarchical structure. The HiNAND2 array includes JGroups, such as Group 1 to Group J, of broken GBL lines associated withJ broken metal2 C_(GBL) capacitors located at topological higher level1throughout each HiNAND2 column. Between any two adjacent metal2 C_(GBL)capacitors of two adjacent Groups, there exist one NMOS GBL-dividedtransistor MGBL (similar to that in HiNAND1 array circuit, see FIG. 2A).For total J HiNAND2 Groups, there are total J−1 GBL-divided transistorsMGBL respectively separating total J broken metal2 capacitors, such asC_(GBL) _(_) ₁ to C_(GBL) _(_) _(J), per one 2D HiNAND2 column.

Along Y-direction of the HiNAND array, each HiNAND2 Group is furtherpreferably divided into L similar Segments, such as Segment 1 to SegmentL, equally or unequally. Each Segment is connected by one local brokenmetal1 LBL line which is located one-level lower than the top levelmetal2 GBL line (or C_(GBL) capacitor) to form a shorter localcapacitor, C_(SEG). Furthermore, each HiNAND2 Segment (associated witheach C_(SEG)) is further divided into n sub-segments of K Blocks, suchas Block 1 to Block K for sub-segment 1, Block K+1 to Block 2K forsub-Segment 2, . . . , till Block K×(n−1)+1 to Block K×n for sub-Segmentn, by n−1 DBL-divided NMOS transistors, MDBLp. Correspondingly eachsub-Segment is associated with a broken-LBL metal1 line that has aparasitic capacitor C_(LBL), which is the smallest capacitance unitconfigured to be pre-charged up to V_(inhibit) voltage for multiple-WLProgram operation. Each HiNAND2 Block further includes N-bit NANDStrings, extending from left to right across whole HiNAND2 array inX-direction. Each HiNAND2 String includes M NAND cells connected inseries and sandwiched by one top and one bottom String-selecttransistors, MS and MG, respectively, where typically M=64 in FIG. 2Bbut can be other integer numbers such as 16, 32 or 128. The preferredHiNAND2 String architecture and process and layout basically isidentical to prior-art 64-cell NAND String in terms of cell size and thebasic Erase, Program and Read conditions.

From 1-sided top N-bit PB viewpoint, all J HiNAND2 Groups with J C_(GBL)capacitors are connected in series starting from the top Group 1C_(GBL1) capacitor directly, then through J−1 MLBLp LBL-dividedtransistors per GBL column to the bottom last Segment C_(SEGJ) capacitorthrough n MDBLp Segment-divided transistors per Segment.

From circuit viewpoint, the top N-bit PB of the HiNAND2 array would beassociated with the smallest RC loading because only one 1×C_(GBL)capacitor but zero resistance along the path when reading the top Group1 WL data without a need going through one transistor resistor MGBL atall with all J−1 transistors M_(GBL) being shut off in non-conductionstate by setting control gate signals DIV_EN[1]= . . . =DIV_EN[J−1]=Vssduring the Group 1 Read and Program operations. In contrast, in HiNAND2array would be associated with the largest RC loading on each GBL lineof each bit of the static PB when one WL is read out from bottom GroupJ, which suffers the highest capacitances of J×C_(GBL) capacitors andJ−1 resistances of J−1 transistors MGBL by setting control gate signalsDIV_EN[1]= . . . =DIV_EN[J−1]≧Vdd+Vt+ΔV_(margin) to fully turn on J−1transistors MGBL to allow full-passage of BL voltage among L Segments ofJ Groups.

In 1-level BL structure, for J−1 broken-GBL metal1 lines per one GBLcolumn, there is no any pull-down transistor device connected to Vss andpower lines. While in the 2-level BL structure, each metal2 C_(GBL)capacitor or divided metal2 GBL line can connect via one dedicatedpull-down transistor to a horizontal (X-direction) bus (e.g., LBLps_1[1]for Segment 1) located at a level even lower than metal1 LBL lines. Inan embodiment, as shown in FIG. 2B, to save the whole HiNAND2 siliconarea, this pull-down device like each MLBLs transistor is removed.Instead, the precharge and discharge of each broken-Group C_(GBL)capacitor can still be realized by connecting each C_(GBL) to eachcorresponding local metal1 LBL line through each correspondingLBL-select transistor MLBLp per Segment by setting control signalsSEG_1[1]= . . . =SEG_1[L]=Vdd and by connecting the local metal1 LBLline (or multiple metal1 broken-LBL lines via corresponding LBL-selecttransistors MLBLs for all sub-segments) to a common metal0 LBLps powerline.

In the following sections, the detailed Multiple-WL and All-BL Read andProgram operations for the HiNAND2 array circuit (FIG. 2B) will beexplained with reference to HiNAND1 shown in FIG. 2A in accordance withthe preferred set of bias conditions shown in FIG. 8 of the presentspecification.

As explained before, this HiNAND2 array has 2-level broken-GBLhierarchical structure. In an embodiment, the single level long metal1GBL line used in conventional NAND array has been replaced by a toplevel metal2 line that is purposely divided into J broken and equalC_(GBL) capacitors. In a specific embodiment, each metal2 broken GBLline length and capacitance can be flexibly divided not equally. Forexample, the last one metal2 broken GBL line associated with Group J ispreferably made much longer than that associated with the first metal2broken-GBL line associated with Group 1 because Group J is the farthestGroup relative to the 1-sided static PB at top of the HiNAND2 array.Thus the dilution of stored charge to the PB would be the worst case.Thus, if it is designed to have larger C_(GBL) capacitance for thefarthest Group J, it can have more charges so as to have less dilutionat PB. In other words, one option of HiNAND array is to have longerbroken GBL line for Group J.

The HiNAND2 array architecture is divided into J Groups by inserting J−1NMOS MHV (˜7V) Group-divided transistors MGBL into each long GBL metal2line. In other words, the conventional one long global metal1 GBL metalline is elevated to a metal2 line and then is divided by J−1 transistorsMGBL into J metal2 broken GBL lines respectively associated with J GBLcapacitors (denoted as C_(GBL) _(_) ₁ to C_(GBL) _(_) _(J) capacitors)per HINAND column.

Each MHV transistor MGBL acts as a bridge device between two adjacentC_(GBL) capacitors associated with the same broken metal2 line. The topend of each metal2 C_(GBL1) capacitor is directly connected to onecorresponding input and output (I/O) of N-bit PB (Page-Buffer). The Jvalue is preferably set to be 16 or 8 but not more than 16 for areliable DRAM-like charge-sharing Read operation and for cutting thepower consumption to 1/16 for one-WL and All-GBL Read of HiNAND2 array.

In an embodiment, there are L lower-level, smaller local metal1 LBLlines or capacitors, C_(SEG), per each corresponding top-level metal2C_(GBL) capacitor. In other words, the length ratio of the local LBLline to GBL line per Group is defined as: Ratio(length)=GBL/LBL=L.

Accordingly, each Group within the HiNAND2 array is divided into LSegments, from Segment 1 to Segment L, laid out in Y-direction. EachSegment in any Group has one dedicated local metal1 bit line associatedwith a C_(SEG) capacitor. Furthermore, each C_(SEG) capacitor is dividedinto n broken-LBL metal1 lines by n−1 LBL-divided transistors MDBLs withtheir gates commonly tied to a control signal DI_1_(—) 1˜n[1], . . . ,or DI_1_1_n[L], depending on it is in which Segment, 1 through L. Eachbroken-LBL metal1 line is associated with a smallest parasiticcapacitor, C_(LBL), connected to K Blocks in parallel. In an embodiment,every local LBL in each Segment, e.g., Segment 1, of Group J connects toone horizontal (X-direction) metal0 power line LBLps_J[1] (see FIG. 2B)via a pull-down transistor MLBLs. In another embodiment, every metal1broken-LBL line in each sub-segment in Segment 1 of Group J is connectedcommonly to the metal0 power line LBLps_J[1] respectively via separatepull-down transistor MLBLs. In yet another embodiment (not shown in FIG.2B), two mirrored Segments (of Group J) share one horizontal metal0power line LBLps_J[L/2]. In this case, there are total L/2 LBLps_1 linesper Group (J) such as LBLps_J[1] to LBLps_J[L/2].

In the example of FIG. 2B, the preferred HiNAND2 array has an optimalvalue of L≦4 for a tradeoff between the precharged supplyprogram-inhibit V_(inhibit) current and number of LBL-dividedtransistors MLBLs per Group. For example, if L=4, that means one Groupcontains four Segments so that minimum four rows of MLBLs transistorsper Group are required for multiple WL Read operation. Of course, wheneach Segment is divided into n sub-segments for a preferred advantage offaster simultaneous multiple WL Program operation, n−1 more rows ofMLBLs transistors are needed per Group. But one LBLps_J power line canbe shared by two adjacent Segments and also shared by n sub-segmentswithin each Segment for area reduction.

Each MLBLs transistor will be used to precharge charges up toV_(inhibit) voltage˜7V during Program and selectively discharge to Vssafter Program operation from LBLps_J metal0 line to each correspondingC_(LBL) capacitor that is initially preset to Vss voltage.

In addition, each MLBLs transistor has second usage to precharge anddischarge charges of Vdd in both metal1 C_(LBL) and metal2 C_(GBL)through the corresponding MLBLs and MLBLp transistors per one Segmentduring Multiple-WL and All-BL Program and Read operations when controlsignals PRE_J and SEG_J are set to Vdd and LBLps_J is set to Vdd in anone-shot pulse.

Each HiNAND2 Jth Group comprises N metal2 GBL lines such as GBL_J[1] toGBL_J[N], extending in X-direction and laid out in parallel to wordlines (WLs). Each long BL column comprises J broken metal2 C_(GBL) lines(or capacitors) and laid out in Y-direction perpendicular to WLs. Onlythe top metal2 C_(GBL) lines are connected directly to N Inputs/outputsof a top circuit block comprising of one N-bit static-PB, one N-bitMultiplier and one N-bit Sense Amplifier (SA).

In an embodiment, each broken C_(GBL) metal2 line of each Segment fromSegment 1 to Segment L within each HiNAND2 Group is laid out in such away with a preferred capacitance or length ratio R=L_(LBL)/L_(GBL)≦1/16,where L_(LBL) is the length of a metal1 LBL line, while L_(GBL) is thelength of a metal2 GBL line. Therefore, by applying a preferredDRAM-like BL charge-sharing technique at least to the farthest Jth Groupfor performing Multiple-WL and All-GBL Read operation in unit of onefull physical WL or a full page on this HINAND2 array, the prechargevoltage (current) can be reduced by above similar ratio.

Firstly, detailed operation of the preferred DRAM-like charge-sharingtechnique for one-WL and All-BL HiNAND2 Read will be explained below.Similarly, the same technique can be easily extended to Multiple-WL andAll-BL Read.

For typical NAND array with one-level BL structure, there are twoschemes of Read operation. One scheme is called as 1-cycle All-BL Read,the other scheme is called as 2-cycle Odd/Even Read. In this HiNAND2array with multiple-level BL hierarchical structure, the All-BL Readscheme is changed to All-GBL or All-LBL Read scheme. The All-BL Readscheme is a Voltage-sensing scheme that requires a precharge of V_(GBL)prior to voltage sensing. The advantage of the voltage sensing scheme islow-power consumption but is prone to fail due to the proximity noisecoupling effect happening between adjacent BLs and adjacent WLs.

A typical All-GBL Read method based on conventional NAND uses avoltage-sensing and precharge-GBL scheme. It is like a 1-cycle Read fromone full physical WL or page of the NAND array. All C_(GBL) capacitorsare first precharged to Vdd-Vt prior to cell sensing. Subsequently, uponsensing, the precharged voltage of Vdd-Vt of each C_(GBL) is then eitherdischarged to Vss for those selected NAND cells in On-state or retainsthe precharged Vdd-Vt for those NAND cells in Off-state in one or moreselected WLs applied with WL Read voltage V_(Rn). The advantage of thisvoltage-sensing scheme is no DC current flow, thus Read powerconsumption is smaller. But the disadvantage is higher rate of producingfault data bits due to the severe coupling noise generated between twoadjacent BL-BL and WL-WL.

The WLs and BLs bias conditions of the selected String in the selectedBlock are listed as: a) Read voltage for a select WL=V_(Rn), n=1 for SLCRead but n=3 for MLC Read; b) V_(R1)=0V for a SLC Read to distinguishone erased E-state and one programmed A-state; c) V_(R1)=0V, V_(R2)=2.5Vand V_(R3)=4V for 4-state MLC Read, where V_(R2) is used to distinguishan A-state and a B-state and V_(R3) is used to distinguish a B-state anda C-state; d) V_(GBL)=0.7V-1.0V is precharged to all metal1 GBL linesinitially prior to reading by shutting off NAND Strings; e) V_(GBL)retains 0.7V-1.0V, if the selected NAND cell's Vt is above V_(Rn), thusno conduction of cell current when V_(Rn) is applied to one selected WLalong with M−1 non-selected WLs=Vpass=6V (assuming it is a M-cell NANDString); and f) V_(GBL) is discharged to 0V, if the selected NAND cell'sVt is below V_(Rn), thus a conduction of cell current happens to pulldown the precharged GBL of 0.7V-1.0V.

Another typical All-GBL Read method in conventional NAND usescurrent-sensing and non-precharge-GBL scheme. The disadvantage of thiscurrent sensing scheme is high read power consumption because of DCcurrent flow. But the advantage is an immunity of severe coupling noisegenerated between the adjacent BL-BL and WL-WL, thus the data is moresolid. Unfortunately, each NAND String's equivalent resistance couldreach up to 1-10 MΩ due to 100 nA String current. Thus, acurrent-sensing scheme for NAND String Read operation has more designdifficulties and challenges than voltage-sensing scheme.

Yet another typical Read operation in conventional NAND usesOdd/Even-GBL Read scheme. Under this type of Read operation, it is likea 2-cycle Read from one full physical WL or page of NAND array. Thewhole physical WL is alternately divided into 2 logic SLC pages withhalves of all GBLs based on odd/even numbered BLs. One half GBLs aredenoted as GBLo lines and the other half GBLs are denoted as GBLe lines.The idea of this scheme is to use the unselected interlaced GBLs as ashielding GBL. For example, when reading all GBLo lines, then all GBLelines are either biased at Vss or Vdd-Vt as the shielding GBLs toprotect the signal development of all GBLo from corruption due to thecoupling noises from discharging between BL-BL.

Recently, the shielding voltage of GBLe or GBLo lines is preferablybiased to be Vdd-Vt, rather Vss, the value of Vdd-Vt is set about 0.7Vto 1.0V, so that WL coupling SBPI scheme is used to eliminate ormitigate the Vpgm WL stress with superior P/E cycles on thoseunselected, programmed cells located in the shielding GBLs. However,this 2-cycle Odd/Even GBL voltage-sensing scheme consumes more powerbecause one time precharge of the whole non-broken C_(GBL) is required.

The WLs and BLs bias conditions of the selected String in the selectedBlock are listed as following: a) Read voltage for a select WL V_(Rn),n=1 for SLC but n=3 for MLC; b) V_(R1)=0V for a SLC to distinguishE-state and A-state; c) V_(R1)=0V, Vr2=1V, V_(R2)=2.5V and V_(R3)=4V forMLC, where the V_(R2) is used distinguish A-state and B-state and V_(R3)is used distinguish B-state and C-state; d) V_(GBLo)=0.7V-1.0V or 0V forGBLo shielding effect when GBLe lines are selected for half-WL Read; e)V_(GBLe)=0.7V-1.0V 0V for GBLe shielding effect when GBLo lines areselected for half-WL Read; f) V_(GBLo)=0V, if the selected NAND cell'sVt in GBLo is below V_(Rn), thus a conduction of cell current; g)V_(GBLo)=0.7V-1.0V, if the selected NAND cell's Vt in GBLo is aboveV_(Rn), thus no conduction of cell current; h) V_(GBLe)=0V, if theselected NAND cell's Vt in GBLe is below V_(Rn), thus a conduction ofcell current; and i) V_(GBLe)=0.7V-1.0V, if the selected NAND cell's Vtin GBLe is above V_(Rn), thus no conduction of cell current.

In an embodiment, Multiple-WL and All-GBL simultaneous Read operationwith a preferred DRAM-like charge-sharing technique in HiNAND2 array isprovided in the present invention with reference to a preferred set ofbiased conditions, as shown in FIG. 8. In HiNAND2 array, both All-GBLand Odd/Even GBL schemes can be adopted for Read operation. But All-GBLRead scheme is preferably adopted over Odd/Even GBL Read scheme forachieving the superior performance and reliability. Therefore, onlydetails about the All-GBL Read scheme would be provided. One stepfurther, Multiple-WL and All-BL Read scheme is proposed below to achieve10-fold or even 100-fold improvements in both Read and Programoperations over conventional NAND by using 2 metal lines only for this2-level broken-BL hierarchical structure without changing the existingcell structures of NAND cell and conditions for operating Read, Program,and Erase. In addition, the HiNAND2 circuit die size at least is keptthe same as the conventional NAND because only few NMOS divided devicesare added in the conventional long and heavy GBL that has hundreds orthousands of NAND cells in one GBL column. Thus many advantages of theHiNAND2 array with 10× to 100× performance improvements overconventional NAND are achieved without causing bigger die size,regardless of 2D or 3D NAND technologies.

Note, HiNAND2 All-GBL Read scheme is a new kind of All-BL Read scheme.Although it still uses a precharge method for all GBL without thedivision into two alternative GBLe and GBLo groups, the prechargedcapacitance is cut down to 1/16 of C_(GBL) of conventional NAND.Correspondingly, the voltage sensing data is multiplied 2-3 folds firstand then fed to latch-type SA and further amplified by a DRAM-SAoperation technique. Details of the charge-sharing, sensing voltagemultiplication, and SA amplification can be found in U.S. patentapplication Ser. No. 14/283,209, filed on May 20, 2014 and U.S. patentapplication Ser. No. 14/316,936, filed on Jun. 27, 2014, all fullyincorporated as references for all purposes.

For example, All-GBL lines of HiNAND2 array are pre-discharged to Vssthrough one MHV (˜7V) device MGBLs through LBLps power line, which ismade of similar String-select NMOS MHV transistor of MS or MG of theHiNAND1 array shown in FIG. 2A. Since the MHV device has a thinner gateoxide compared to a HV (20V) of transistor used in the conventionalNAND, plus the broken-GBL capacitance is only 1/16 of unbroken-GBLcapacitance, thus the discharge and charge speed of broken GBLcapacitance is at least about 8-fold faster due to the smallerconducting transistor's resistance.

As an example, a set of bias conditions of HiNAND2 One-WL & All-GBLsimultaneous Read operation are listed here, which is like a 1-cycleRead from one full physical WL or page of HiNAND2 array. For oneselected page in the selected Block, the WLs and BLs bias conditionsinclude 1) Read voltage for a select WL=V_(Rn), n=1 for SLC Read, butn=1, 2, 3 for MLC Read; 2) V_(R1)=0V for a SLC read to distinguish E andA state; V_(R1)=0V, V_(R2)=2.5V, and V_(R3)=4V for a MLC read. 3) V_(R2)is used to distinguish A-state and B-state. V_(R3) is used todistinguish B-state and C-state.

The whole concept of the HiNAND2 Read operation is to use charge-sharingscheme like DRAM along with the WL-voltage. The precharge is stillneeded for this HiNAND All-GBL Read, but not to precharge the long andheavy unbroken GBL capacitor in the conventional NAND to Vdd-Vt thatwould consumes too much precharge-power due to each big GBL capacitanceof 3-5 pf, instead, to precharge each broken metal2 C_(GBL) capacitancein the HiNAND2 array which can be reduced to only 1/16 of original bigGBL capacitance of 3-5 pf to become about 0.1875 pf˜0.3125 pf in layout.Thus the precharge current can be also reduced to 1/16 if the prechargedvoltage is same as Vdd-Vt. For HiNAND charge sensing, the prechargedvoltage is preferably changed to Vdd for more stored charges with abigger signal for more reliable charge-sharing operation. The HiNAND2Multiple-WL and All-GBL Read operation is divided into eight operationsteps/cycles in accordance with various biased conditions shown in FIG.8 and FIG. 9 of the specification as well as the HiNAND2 array circuitshown in FIG. 2B of the specification.

Step 1: To simultaneously predischarge the voltages of all brokenN×LBL/N×GBL capacitors to multiple mixed power/Vss lines denoted as aLBLps line in one or multiple Segments in one or multiple Groups.

In an embodiment, the HiNAND2 array includes preferably only one powerline of LBLps per one Segment within one Group for saving silicon area.Thus there are several ways to pre-discharge each broken C_(GBL) andassociated C_(SEG) capacitors. For example, each Group has J Segments,thus it has J LBLps lines. Any charges stored in each C_(SEG) can beeasily discharged through each corresponding connection device MLBLs bysetting its gate signal PRE_1[J] to Vdd and connecting correspondingLBLps line to ground Vss. The charges stored in each bigger C_(GBL) perGroup can have 1 to J discharged paths through 1 to J MLBLs transistorsto corresponding 1 to J LBLps lines. But more MLBLs transistors, morePRE_1[J] control lines have to be coupled to Vdd, thus more powerconsumption is resulted. Additionally, each broken C_(GBL) capacitanceis set to be only 1/16 of each conventional unbroken long and heavyC_(GBL), thus one LBLps line is selected for discharging a selected oneC_(GBL), one C_(SEG), and one corresponding selected NAND String.

Thus the selected PRE, SEG, SSL control signals are coupled to Vdd andthe LBLps to Vss as seen in the first column of table in FIG. 9. If theSegment 1 of Group 1 are selected, then V_(PRE) _(_) _(1[)1]=V_(SEG)_(_) _(1[)1]=V_(SSL[1])=Vdd and V_(LBLps[1])=Vss. The signalscorresponding to rest J−1 Segments V_(PRE) _(_) _(1[J])=V_(SEG) _(_)_(1[J])=V_(SSL[1])=Vss and V_(LBLps[1])=Vss. Since the discharge currentis flowing through each corresponding MHV transistor MLBLssimultaneously and collectively, thus the discharge time is as fast as100 ns or less for all selected LBL and GBL lines and capacitors.

Step 2: To precharge one selected local smaller C_(SEG) and oneassociated C_(GBL) per column, where C_(SEG)<<C_(GBL). Severalembodiments of the precharging method for HiNAND2 Multiple-WL and All-BLRead operation are provided.

In an embodiment, Read operation is to randomly read out data preferablyfrom All-GBL and J-WLs simultaneously based on only one same selected WLaddress per Segment per Group, where J≦16. The HiNAND2 arrayarchitecture allows total J pages of data to be read simultaneously outfrom J different Groups but on the basis of one WL per one Group. Inother words, a multiple-WL randomly Read scheme means each selected WLin different Segment and Groups remain at a same position incorresponding selected NAND String with a same address. Differentaddress multiple-WL Read scheme is possible if the Block's WL addresscan be locked in for the random-select ones.

In another embodiment, Read operation is to read multiple WLssimultaneously and preferably from one Segment of one or more Groups. Inthis embodiment, the HiNAND2 scheme flexibly allows read more than oneWL from one or more selected Segments within one or more Groupssimultaneously. For example, it allows to read L pages (WLs) of datasimultaneously from L Segments (one WL per one Segment basis) of theselected Groups which are laid out near top PB with much less C_(GBL)loading for more reliable charge-sharing SA operation.

The preferred precharge happens on N shorter LBL metal1 C_(SEG)capacitors that have only 1/16 of each broken C_(GBL) capacitance. TheseN LBL lines include LBL_1[1] to LBL_1[N] in the selected multipleSegments per Group. Unlike Vdd-Vt precharge voltage for prior-art NANDthrough a 20V long-channel device with a very slow precharge time (˜5μs), the precharged LBL voltage is preferably set to be Vdd of 1.8V forthe HiNAND2 array through a MHV (7V) transistor MLBLs by setting thegate control signals PRE and SEG to Vread>Vdd so that a full Vdd passageto N C_(SEG) capacitors, as shown in the second column of table in FIG.8. Other associated signals such as the selected SSL, LBL, and GBL areset to Vdd but the unselected SSL, LBL, and GBL are set to Vss. Vddvoltage greater than 1.8V can be used as well but the precharged powerconsumption would be increased accordingly.

In addition to precharge the selected LBLs and GBL lines (orcapacitors), the selected and unselected WLs in the selected Block inthe selected Segments of a selected Group are also preferably prechargedto V_(R) and Vread respectively and simultaneously to save total timedelay of Read operation. V_(R) voltage is Read voltage for distinguishE-state or A-state of a selected NAND cell. Vread voltage typically isset to be around 6V. The Vread voltage for unselected WLs is calledVpass.

As a result, the precharge time of the selected C_(SEG) and C_(GBL) canbe completed within 100 ns, which is very fast. But Vpass precharge timefor unselected WLs is much longer up to few μs. Thus among all cycletime of the BL and WL precharge step, the Vpass precharge time is thebottleneck. Note: The voltage of Vdd-Vt˜0.9V in prior-art NAND atVdd=1.8V. Table 1 shows a comparison of precharge step performedrespectively for conventional NAND and HiNAND2.

TABLE 1 Comparison of Conventional precharge NAND HiNAND2 Prechargedvoltage 0.9 V(1X) 1.8 V(2X) Precharged 100% = N × 6.25% = N ×capacitance C_(GBL(unbroken)) C_(GBL(broken)) + N ×C_(LBL(broken or non-broken))~N × (1/16)C_(GBL(unbroken)) Precharged BL100% 1.25% current ratio: CV (1-WL & All-GBL) (1-WL & All-GBL)Precharged BL 100% 6.25% current ratio: CV (1-WL & O/E GBL) (1-WL &All-GBL) Precharged 100% ~2% (negligible) GBL time Precharged WL 100% 100% time (one block) Precharged WL 100% 6.25% time (16 blocks) Note:WL precharge time means Vpass precharge time on 63 unselected WLs for a64-NAND String. The simultaneous precharge on multiple selected WLs ofthe selected Blocks tremendously saves time delay for this cycle of Readoperation.

Alternatively in another embodiment, as shown in FIGS. 2A and 2B, eachSegment is further divided into n sub-Segment by n−1 NMOS 1-polytransistors. Thus each LBL metal1 line is divided into n broken-LBLmetal1 line associated with an even smaller parasitic capacitor C_(LBL).In this case, the precharged voltage through independent power lineLBLps_J per Segment, the precharge operation can be performed on eachsub-Segment independently and simultaneously for multiple sub-Segmentsin different Segments of one or more Groups to a higher voltage up toV_(inhibit)˜7V for taking advantage of further reduced power inprecharging step while still has sufficient voltage level aftercharge-sharing that can be amplified by the Multiplier in the PB to avalue close to 1V for proper charge-sensing by Latch SA.

Step 3: To discharge C_(SEG) and C_(GBL) on one or multiple selected WLswith V_(R). After all N×LBL associated N×GBL broken lines (orcapacitors) are fully precharged to 1.8V simultaneously, the desired setof various control voltages of GSL, SSL and 64 WLs are respectivelyapplied for one selected WL and multiple unselected WLs per selected oneor more Blocks in the selected Segments and Groups for a preferredMultiple-WL & All-GBL simultaneous Read or Program-Verify operation withall LBL-select transistors MLBLp (connected between the LBLs and GBLs)being at off-state.

For example, for a SLC Read, then the selected WL=0V, and unselected 63WLs=Vpass=6V and GSL[1]=Vread but SSL[1]=Vdd. For part of N×C_(SEG), theprecharged voltage will start to discharge from initial 1.8V to Vss ifthe corresponding NAND cells' Vt=Vte<−0.7V, an E-state, within apredetermined discharge time. For the remaining part of N×C_(SEG) theirprecharged voltage will not discharge and retain its initial 1.8V if thecorresponding NAND cells' Vt>0, which is A-state.

Thus, after the Step 3 of Multiple-WL & All-BL Read operation, the LBLlines in the selected Segments and the broken GBL lines in the selectedGroups will trap respective Vss and 1.8V voltages in accordance with thestored NAND data pattern on the selected WL of the selected Block in theselected Segment in the selected Group of this HiNAND array. After J-WL& All-BL Read, either 1.8V or Vss will be stored separately in allN×GBL_1 to N×GBL_J capacitors in accordance with the stored data inmultiple WLs when all DIV_EN[1]= . . . =DIV_EN[J−1]=Vss.

The comparison of the discharged time between HiNAND2 and conventionalNAND are summarized in Table 2 below. Note the discharge happens notonly on 1-WL & All-GBL of one selected Block in accordance with one WLdata but also happens on Multiple-WL & All-GBL in accordance with J WLdata. The final read data patterns are stored in J isolated brokenC_(GBL) capacitors before being dumped to PB. Note: The voltage ofVdd-Vt=0.9V in prior-art NAND at Vdd=1.8V.

TABLE 2 Comparison of discharge NAND HiNAND2 Initial voltage before 0.9V(1X) 1.8 V(2X) discharge Discharged capacitance 100% = N × 6.25% = N ×C_(GBL(unbroken)) C_(GBL(broken)) + N × C_(SEG)~N ×(1/16)C_(GBL(unbroken)) Discharged GBL/LBL 1X 1X current DischargedGBL/LBL time 100% <12.5% for 1-WL and All-GBL scheme Discharged GBL/LBLtime 100%   <1% for 16-WL and All-GBL scheme

In this discharge operation, the HiNAND2 architecture has almostone-order of improvement over state-of-art NAND in 1-WL & All-GBL Read.Assuming M(J)=16 in FIG. 8, then 16-WL & All-GBL discharging time isalmost zero as compared to the conventional NAND. This is a big savingin NAND Read time.

For example, a typical SLC discharged time is about 10 μS for one WLread. For 16-WL read, then the total discharge time is about 160 μS. Forthis HiNAND2 simultaneous multiple-WL & All-GBL Read operation, thetotal discharging time is nearly 0. This is a dramatic improvement inNAND Read time record.

Step 4: To perform charge-sharing operations of C_(SEG) and C_(GBL) forthe multiple-WL & All-GBL Read operation.

In an example with J=16 (or 16 Groups in the HiNAND array), after theprevious discharge cycle, 16 respective C_(GBL) capacitors that storethe isolated voltages of 0V or 1.8V in accordance with the correspondingstored data in 16 selected WLs in 16 NAND Groups of the HiNAND2 arrayaccording to an embodiment of the present invention. These 16 C_(GBL)capacitors are lined up from bottom to up of each GBL column such asGBL_J in bottom Group J to GBL_1 in top Group 1. Any two adjacentC_(GBL) capacitors are isolated by 15 off-state NMOS GBL-selecttransistors such as MGBL15 to MGBL1 from GBL bottom to GBL top, which isdirectly connected to N-bit PB.

The charge-sharing step/cycle (Step 4) can be divided into 15 sequentialsub-steps for 16-WL and All-BL simultaneous Read or Program-Verifyoperation. Note, the simultaneous Multiple-WL & All-BL Read orProgram-Verify operation means at least the following three steps: step1 for pre-discharging LBL/GBL, step 2 for precharging LBL/GBL, and step3 for discharging LBL/GBL can be performed simultaneously. Thus the timedelay has been cut to be almost negligible in HiNAND2 as compared to theconventional NAND. But from the Step 4 to Step 8 in FIG. 8 and FIG. 9,the remaining operation steps cannot be performed simultaneously becauseonly one shared PB and GBL path to the PB. The 16-WL data stored inrespective C_(GBL) capacitors have to be sent to the PB in sequence thatstarts from top Group 1, followed by Group 2, . . . , and lastly, GroupJ, which is Group 16 in the present example.

In a first sub-step, only the N×C_(GBL) of GBL_1[1]= . . . =GBL_1[N] intop Group 1 would be evaluated in top N-bit PB with N-bit Multiplier andN-bit SA. The rest of N×C_(GBL) capacitors in Group 2 to Group 16 wouldbe completely isolated from each other during the read or dataevaluation cycle of Group 1 to avoid data contention in each long GBLline.

In the Group 1 data evaluation Read cycle, actually, no charge-sharingoccurs with other C_(GBL) capacitors of the rest 15 Groups. Thus thevoltages of Vss and Vdd (1.8V) are 100% to be coupled into the PB fordata evaluation without degradation. Thus, the biggest signal of Vdd andVss are sensed by the PB when the selected WL data is read.

Once the first N-bit C_(GBL) voltages have been loaded in parallel intothe only one Voltage-multiplier in the N-bit PB on top of the HiNAND2array for data evaluation, the voltage of first N-bit C_(GBL), GBL_1[1],. . . , GBL_1[N], has to be discharged to Vss first. In other words,GBL_1[1]= . . . =GBL_1[N] are reset to Vss before second N-bit C_(GBL)capacitors that store new voltages of second WL data to be transferred.

But before turning on second N-bit C_(GBL) capacitors of GBL_2[1] toGBK_2[N] to connect to the first N-bit C_(GBL) capacitors GBL_1[1] toGBK_1[N], the N×MLBLp have to be shut off first to isolate the selectedBlock in Group 1 from the selected Block in Group 2 by setting signalSEG_1[1] to Vss before setting the divided transistor gate signalDIV_EN[1] to Vread to connect N×GBL_1[2] to N×GBL_1[1]. But because theconnection is preferably only happening between N×GBL_1[2] toN×GBL_1[1]. The rest connections of N×GBL_1[2] to N×GBL_1[16] are stillkept isolated from each other. Thus, the rest of divided transistor MGBLgate voltages are set to be Vss, such as DIN_EN[2]=DIN_EN[3]= . . .=DIN_EN[15]=Vss.

Since the voltages of each GBL_1[2] is either Vss and Vdd of dividedtransistor 1.8V to share with the identical C_(GBL) of each GBL_1[1]with Vss, then the final voltages would be Vss and 0.9V stored in bothGBL_1[1] and GBL_1[2] with the gate signal DIV_EN[1]=Vread=6V.

The final charge-shared voltages of either Vss or 0.9V for the secondN-bit C_(GBL) capacitors would be coupled to N-bit Multiplier and N-bitSA in the N-bit PB on top for data evaluation. The sensed voltage of0.9V from Group 2 is the second largest signal of a second sub-step ofthe Multiple-WL and All-BL Read and Program-Verify operations.

Since the VREF in SA is dynamically set to be ½ of sensing voltage. InGroup 2 the sensing voltage is 0.9V. Thus, the VREF=0.45V. This ΔV=0.45Vis big enough without a need of amplification by the Multiplier. Thus,the multiplier function can be temporarily disabled to allow the directcoupling of 0.9V and Vss from each GBL to one input of eachcorresponding SA to skip the Multiplier function in between. This wholeoperation can be controlled by the on-chip State-machine once it detectsthe data either from Group 1 or Group 2.

Once Group 2 WL data are successfully evaluated by the PB and data issent out to NAND memory system, all capacitors of GBL_1[1] to GBL_1[N]and GBL_2[1] to GBL_2[N] have to be reset to Vss for the third WL dataevaluation read out from Group 3, subsequently in a third sub-step.Similarly, the Read and Program-Verify or evaluation of the third WL orpage in Group 3 repeat the processes as explained above.

The voltages of Vss and 1.8V of third N-bit C_(GBL) capacitors fromGBL_3[1] to GBL_3[N] would be shared by both GBL_1[1] to GBL_1[N] andGBL_2[1] to GBL_2[N] capacitors with initial Vss voltage. Thus thevoltages would become ⅓ due to charge-sharing in 3 identical brokenC_(GBL) by setting divided transistor gate signal DIV_EN[3] toDIV_EN[15]=Vss. Similarly, both SEG_1[1] and SEG_1[2] signals are set toVss to have the selected Blocks of Group 1 and Group 2 being isolatedfrom Group 3 during the third WL data evaluation. The final WL sensedvoltages of Group 3 are either 1.8V/3=0.6V (high) or Vss (low). Since0.6V is still a large reliable signal for SA, thus the Multiplierfunction can be skipped again during Group 3 WL-page evaluation.

The above sub-steps of multiple-WL and All-GBL Read and Program-Verifyoperations will be repeated and finalized when the last NAND page-datain Group 16 is completed. Since the sensed voltage of GBL_J will begetting smaller and smaller when more C_(GBL) capacitors to share the1.8V and 0V, using a Multiplier to increase the weak signal of GBL_J isrequired. In this 16-group HiNAND2 array, each Multiplier is enabled tofunction between each corresponding SA and C_(GBL) after Group 4. TheMultiplier is configured to amplify GBL signal V_(GBL) at least 3 timesto be sensed reliably by a DRAM-like latch-type SA (see reference patentapplication Ser. No. 14/283,209, commonly assigned).

All Multiplier operation and chare-sharing operation can be completedwithin 200 ns. Thus, the true bottleneck of Multiple-WL and All-GBL Readoperation speed is the time delays during precharge and discharge ofbroken GBL capacitor. As shown above, these two time delays aredramatically reduced when the simultaneous Multiple-WL and All-GBL andchare-sharing Read scheme under the HiNAND2 array with preferred 2-levelbroken-BL hierarchical structure.

Step 5: To perform a voltage amplification of sensed V_(GBL) by usingone preferred Multiplier that is associated with one SA within the N-bitPB on top.

In an specific embodiment, in the HiNAND2 architecture, a Multiplier isconfigured to bear an amplification factor that is at least greater than2 but preferred to be no greater than 5, as a tradeoff as an optimalmultiplier with desirable operating time and reliable SA operation. EachMultiplier is preferred to include 3 or more capacitors being configuredeither in series or in parallel with multiple timing control clocks toallow the capacitors to multiply the finally sensed voltages coupled toeach GBL capacitor on top of HiNAND2 array. For example, for thevoltages sensed from Group 10 is 1.8V/10=0.18V. This signal is too weakto be reliably evaluated by each corresponding Latch-type SA. Thus, theMultiplier function is preferably enabled to have an amplificationfactor of 3 to increase 0.18V by 3 times to 0.54V for the subsequentreliable evaluation of the SA.

The required amplification of the SA has to take consideration of themismatched characteristics of paired inputs of MOS transistors of eachSA. The details can refer to the explanation of a Multiplier circuit ofFIG. 2A in later sections of the specification.

Step 6: To perform the data evaluation at Multiplier's output port byusing a DRAM-like, Latch-type SA.

Again, this Latch-type SA has two inputs connected to one sensed voltagecoupled from each GBL capacitor and one input coupled to a VREF with apreferred programmable values. Similarly, this SA has one clocked PMOSdevice coupled to Vdd and one clocked NMOS device coupled to Vss for2-stage amplification and is commonly used in DRAM SA operation. Thusthe details of this operation will be skipped here and can refer to theU.S. patent application Ser. No. 14/283,209, filed May 20, 2014,commonly assigned and incorporated by references herein for allpurposes.

Step 7: To load each sensed N-bit WL data into on-chip N-bit Cachememory. This operation is essentially a final step of each Multiple-WLand All-GBL Read (or Program-Verify) operation.

Step 8: To read page (WL) data through this Cache, which can be sent tooff-chip Flash controller sequentially. Once the first WL page-data issent out to Cache memory, the second WL from Group 2 to last 16th WLfrom Group 16 would be sent sequentially in the form of fast pipelineformat. In particular, the above operations associated with step 2)through step 6) are repeated. In the NAND spec today, the fastest readdata rate is 2.5 ns 8×I/O in DDR2 operation. The time for sending out asmall page is 512 B. It takes about 1.28 μs (2.5 ns/B×512 B/page=1.28μs/page). For a large 8 KB page data per one physical WL, it will take20.48 μs (1.28 μs×16=20.48 μs).

But the averaged NAND spec of a SLC page (WL) Read is 25 μs, 75 μs for a4-state MLC Read, 175 μs for an 8-state TLC Read, and is about 375 μsfor a 16-state XLC Read. Thus, for the Multiple-WL and All-GBL Readoperation, the dramatic reduction in Read latency can flexibly provide amost powerful simultaneous Read and Program operation in ALL NANDGroups. It just needs a well planning of operating HiNAND2 arraycontrolled by the on-chip smart State-machine or CPU.

FIG. 3 is a block diagram of a Page Buffer circuit for both the HiNAND2and HiNAND1 arrays according to embodiments of the present invention.This diagram is merely an example, which should not unduly limit thescope of the claims herein. One of ordinary skill in the art wouldrecognize many other variations, modifications, and alternatives. Asshown, a preferred embodiment of a N-bit Static PB is configured to beinserted in a middle position between a first set of Groups (1 to D) anda second set of Groups (D+1 to J). This middle Static PB can be appliedto both HiNAND2 and HiNAND1 arrays with two sets of N-bit outputs fromStatic Data Registers to respectively connect the first set and secondset of N-bit HiNAND Groups. In a specific embodiment, the HiNAND array,either HiNAND2 or HiNAND1, is divided into two equal N-bit sub-arraysthat are mirrored in Y-direction but with half-density separated by themiddle Static N-bit PB. The middle Static PB includes one static N-bitCache Register and one static N-bit Data Register. The definition ofStatic PB means that the data bits are made of real latch circuits thatcan hold data forever as long as no power loss. Conversely, the DynamicData or Cache Registers are made of either broken GBL lines or brokenLBL lines to hold the Program-bit pattern of Program-Inhibit voltagepatterns in the HiNAND array of the present invention.

As illustrated in previous sections, from one middle PB prospect, thefarthest Group is Group J in the lower HiNAND sub-array (with the secondset of Groups) and Group 1 in the upper HiNAND sub-arrays (with thefirst set of Groups). If these two farthest Groups, Group 1 and Group J,are made with the same equal length of the broken GBL line and SegmentLBL line as Group D−1, Group D, Group D+1, and Group D+2 that near themiddle Static PB, then they suffer the highest loss of charge-sharingsignal voltage level when sensed by the middle Static PB. Therefore, theminimum capacitance of each broken GBL or LBL is determined by theworst-case charge-sharing effect in the farthest Groups such as Group Jand Group 1 if all GBL and LBL metal lines are made with an equal lengthor capacitance.

Each bit of N-bit PB has two set of N-bit outputs. The first set N-bitoutputs are connected to the upper HiNAND sub-array from Group D up toGroup 1 which is the farthest Group and the second output is connectedto the lower HiNAND sub-array from Group D+1 to Group which is anotherfarthest Group. This HiNAND array with a middle Static PB scheme has anadvantage of owning two Groups with faster operation speed and loweroperation power, such as Group D and Group D+1, and one N-bit PB forboth upper and lower HiNAND sub-arrays. Thus, the silicon area isreduced and the preferred DRAM-like Charge-sharing sensing scheme andRecall to restore the programmed WL patterns can be executed moreefficiently than 1-sided Static PB. The disadvantage is the metal2broken GBL has to pass across the middle PB to reach the first set ofGroup D to Group 1 and the second set of Group D+1 to Group J in thisHiNAND2 array.

FIG. 4A is a simplified circuit diagram of a HiNAND2 array of FIG. 2Bperforming Sample & Hold (S/H) functions of a Multiple-WL TLC Programoperation according to a specific embodiment of the present invention.As an example, the HiNAND array has been divided into 8 Groups. EachGroup large metal2 GBL capacitor (or GBL line) is divided into 8Clusters of 4-Segment metal1 capacitors through 8 divided GBL transistorof MLBLp. Each broken Group metal2 line has eight 4-Segment metal1capacitors connected in parallel. Each 4-Segment Cluster includes oneSegment being assigned to be one Dynamic Page Buffer (PB) and threeSegments being assigned to be Dynamic Cache Registers. The assignmentsare preferably rotated among these 4 Segments. FIG. 4A shows that thefirst Segment of Cluster 1 in the dispersed eight Groups is assigned tobe one Dynamic PB but the next three Segments are assigned to be threecorresponding Dynamic Cache Registers for storing one corresponding3-bit TLC data. The S/H functions can be also applied to HiNAND1 as wellwith minor modifications but the description is skipped here.

In this example, N GBL columns are being divided into 8 broken Groups of8 equally-segmented N-bit large metal2 capacitors, C_(GBL), such asGBL_1[1] to GBL_1[N] in Group 1 and GBL_8[1] to GBL_8[N] in Group 8through 7 N-bit divided GBL transistors, MGBL, with 7 gates tied to 7respective signals of DIV_EN[1] to DIV_EN[7].

In other words, each Group's GBL metal2 line forms a metal2 capacitor,C_(GBL), and is connected to 32 Segments with 32 lower-level metal1capacitors C_(SEG). Each Segment is termed as one Dynamic Registercomprising one metal1 capacitor C_(SEG) in series with one Segmentdivided transistor MLBLp with its gate tied to a SEG signal inaccordance with FIG. 2B. Totally, there are 32 MLBLp transistors withtheir gates tied to 32 respective SEG_1 to SEG_32 per C_(GBL) per Group.

Each Group C_(GBL) is connected 32 Segments, thus 32 Dynamic Registers.The capacitance of each C_(GBL) is 32 times of each C_(SEG) in 2D HINANDarray in this example. In other words, C_(GBL)=32×C_(SEG).

Referring to FIG. 4A, in each Group, 4 out of 32 adjacent DynamicRegisters are formed as one TLC storage center with a preferred jobRotation Assignment as each 3-bit TLC data program operation isperformed. In one TLC storage center, one of four metal1 C_(SEG)capacitors with a Cluster is circled and assigned to be a Dynamic PB fortemporarily storing 1-bit of “0” of Program code or “1” ofProgram-Inhibit code. Three out of four C_(SEG) capacitors belonging tothe same Cluster marked with dash-box are termed as 3-bit Dynamic CacheRegisters for storing one 3-bit TLC programmed data in one physical NANDcell in one selected WL. The “0” of the programmed code is convertedinto 0V but “1” of the program-inhibit code is converted into aV_(inhibit) voltage level as the storage charges stored in each C_(SEG)capacitor. In the HiNAND2 array of the present invention, the preferredV_(inhibit) voltage is defined as Vdd≦V_(inhibit)<10V, and typicallyV_(inhibit)=7V. Similarly, 3-bit of each TLC data, data “0” is alsobeing converted into 0V and data “1” is converted into the V_(inhibit)voltage level as the storage charges stored in 3 respective C_(SEG)capacitors of 3 Dynamic Cache Registers marked with same dash-box.

The detailed biased voltages of all key control signals for 2D HiNANDarray are set in accordance with the fourth step of multiple-WL andAll-GBL simultaneous Program and Recall operations shown in FIG. 10,FIG. 11, FIG. 12, and FIG. 13 of this specification. Table 3 belowsummarizes TLC Rotation assignment of four C_(SEG) capacitors. The firstTLC Rotation assignment is shown in FIG. 4A.

TABLE 3 TLC Rotation assignment of 4 C_(SEG) capacitors first C_(SEG)second C_(SEG) third C_(SEG) fourth C_(SEG) capacitor capacitorcapacitor capacitor 1^(st) assignment Dynamic PB Dynamic Dynamic DynamicCache Cache Cache 2^(nd) assignment Dynamic Dynamic PB Dynamic DynamicCache Cache Cache 3^(rd) assignment Dynamic Dynamic Dynamic PB DynamicCache Cache Cache 4^(th) assignment Dynamic Dynamic Dynamic Dynamic PBCache Cache Cache

For a MLC Recall and Program operation, then only three C_(SEG)capacitors are required for three Rotation assignments as summarizedbelow in Table 4.

TABLE4 MLC Rotation assignment of 3 C_(SEG) capacitors first C_(SEG)second C_(SEG) third C_(SEG) capacitor capacitor capacitor 1^(st)assignment Dynamic PB Dynamic Dynamic Cache Cache 2^(nd) assignmentDynamic Dynamic PB Dynamic Cache Cache 3_(rd) assignment Dynamic DynamicDynamic PB Cache Cache

For a SLC Recall and Program operation, then only two C_(SEG) capacitorsare required for two Rotation assignments as summarized in Table 5below.

TABLE 5 SLC Rotation assignment of 2 C_(SEG) capacitors first C_(SEG)second C_(SEG) capacitor capacitor 1^(st) assignment Dynamic PB DynamicCache 2^(nd) assignment Dynamic Dynamic PB Cache

Referring again to FIG. 4A, all Dynamic Cache Registers are rotationallyassigned in only 3 C_(SEG) capacitors of Group 1 for superior restoringeach TLC programmed data back to the 3-bit Static PB registers on top ofHiNAND array. But all Dynamic PB Registers are also rotationallyassigned to all selected WLs in all selected Groups. Note, each SegmentDynamic Data Register or Dynamic Cache are preferably made of metal1 LBLlines with C_(SEG) capacitors corresponding to respective Segments withone dedicated precharge transistor and precharge power line as seen fromon enlarged figure with gate tied to SEG_32[2]. The prechargedtransistor is MBLs with gate tied to PRE and supply line is LBLps. Sincethe details have been explained in previous pages of this application,thus it is skipped here for simplicity of description.

FIG. 4B is a simplified circuit diagram of a HiNAND2 array of FIG. 2Bperforming Sample & Hold functions of a Multiple-WL TLC Programoperation according to another specific embodiment of the presentinvention. As shown, the assignment of 4-Segment metal1 capacitors arerotated with the last Segment of Cluster 8 in the dispersed eight Groupsbeing assigned to one Dynamic PB and the first three Segments of Cluster8 being assigned to be three corresponding Dynamic Cache Registers forstoring another one corresponding 3-TLC data. Note, all Dynamic CacheRegisters are also rotationally assigned in only 3 C_(SEG) capacitors inGroup 1 similar as FIG. 4A.

In summary, both FIG. 4A and FIG. 4B show a first preferred option ofMultiple-WL and All-GBL simultaneous Program operation being performedin only one selected Group, Group 1, not dispersed in eight Groups,Group 1 through Group 8. Similarly, all 8 WLs can be selected in anyonly one Group among Group 1 through Group 8. This can be referred asConsolidated Multiple-WL and All-BL simultaneous Program operationbecause the selected Multiple WLs are only from one selected Group.

FIG. 4C is a simplified circuit diagram of a HiNAND2 array of FIG. 2Bperforming Sample & Hold functions of a Multiple-WL TLC Programoperation according to another specific embodiment of the presentinvention. As shown, the assignment of 4-Segment metal1 capacitors arerotated with the first Segment of all eight Clusters in Group 1 beingassigned to one Dynamic PB and the next three Segments in each Clusterbeing assigned to be three corresponding Dynamic Cache Registers forstoring another one corresponding 3-TLC data.

FIG. 4D is a simplified circuit diagram of a HiNAND2 array of FIG. 2Bperforming Sample & Hold functions of a Multiple-WL TLC Programoperation according to another specific embodiment of the presentinvention. As shown, the assignment of 4-Segment metal1 capacitors arerotated with the first Segment of all eight Clusters in Group 8 beingassigned to one Dynamic PB and the next three Segments in each Clusterbeing assigned to be three corresponding Dynamic Cache Registers forstoring another one corresponding 3-TLC data.

FIG. 4C is and FIG. 4D show a second preferred option of Multiple-WL andAll-GBL Simultaneous Program being performed in all 8 dispersed groups,Group 1 through Group 8. In other words, 8 program WLs are selected fromGroup 1 through Group 8 one WL per one Group, respectively andsimultaneously. This can be referred as Dispersed Multiple-WL and All-BLSimultaneous Program operation because the selected Multiple WLs aredispersed in multiple selected Groups.

Note, when Group number is larger than the totally allowed selectedmultiple WLs, then only Multiple-WL out of all total Groups are selectedfor Multiple-WL and All-BL Program per each program pulse. TheMultiple-WL Program will be continued and it will end until all desiredWLs in HiNAND groups being programmed. The detailed description of FIG.4C and FIG. 4D are skipped because their operations are substantiallythe same as FIG. 4A and FIG. 4B.

In summary, FIG. 4A and FIG. 4B show the first preferred ConsolidatedMultiple-WL and All-GBL simultaneous Program with different Rotationassignments, while FIG. 4C and FIG. 4D show the second preferredDispersed Multiple-WL and All-GBL simultaneous Program. Alternatively, amixed Consolidated and Dispersed of Multiple-WL and All-GBL simultaneousProgram operations can be also implemented in the HiNAND array designbut preferably keeping all Dynamic PBs in Group D and Group D+1 when amiddle PB architecture is used as shown in FIG. 3.

FIG. 5A is a circuit diagram of 1-bit static PB circuit that comprisesone Multiplier circuit, one 1-bit Sense Amplifier circuit and one 1-bitSLC Data Register, along with one Y-pass circuit, One Cache Register,one I/O Control and multiple I/O [1:X] pins for Multiple-WL and All-GBLSimultaneous SLC operations for both HiNAND1 and HiNAND2 arraysaccording to an embodiment of the present invention. As shown, the 1-bitSLC-static PB 500 includes one Multiplier 502, one 1-bit SA 504, and one1-bit SLC Data-Register/PGM-Buffer 506 along with one Y-pass circuit510, One Cache Register 512, one I/O Control 514, and multiple I/O [1:X]pins 522 for J-WL and All-GBL Simultaneous SLC operations for bothHiNAND1 and HiNAND2 arrays. Note, in this SLC circuit, Data-Register andPGM-Buffer are combined into one PB 500. The Data-Registers used tostore the stored voltages of each smaller C_(SEG) or each bigger C_(GBL)capacitors. In contrast, each bit of PGM-Buffer is used to store 1-bitProgram and Program-Inhibit data pattern in DL from eternal I/O or fromthe stored C_(SEG) and C_(GBL) capacitors.

Furthermore, each SLC Data Register 506 includes one 1-bit ProgramBuffer and each SA 504 includes one DRAM-like SA with two inputs. Oneinput is connected to Multiplier's amplified output signal OUTP andanother input is connected to reference signal VREF.

The DRAM-like sense amplifier operations are like analog-to-digitalconvention with 2-cycle amplification steps such as Vdd clock and Vssclock. In particularly, the 1-bit Static PB 500 includes one Multiplier502 associated with each GBL line for Multiple-WL and All-BL Read,Program-Verify, and Erase-Verify operations. The Multiplier 502 is usedto amplify each detected GBL voltage V_(GBL) if it is smaller than 0.4Vas developed at each of top GBL nodes of N GBL lines GBL_1[1] throughGBL_1[N]. The amplified voltage signals then are respectively passed toN corresponding BLP nodes. The decision with or without including theMultiplier 502 between Latch-type SA 504 and GBL sensing node of thepresent HiNAND2 array is determined by the location of selected Groupand signal voltage levels of the detected at GBL node.

As explained earlier in this description, the sensed voltage level fromGBL_1[1] in top Group 1 and GBL_J[1] of bottom Group J after DRAM-likeCharge-sharing effect will have different voltage dilutions if each GBLcapacitance is equally divided in length. In the case of theequally-divided GBL capacitor, the Charge-sharing design is based on thefarthest Group J which has the lowest Charge-sharing sensed voltagelevel due to all J GBL capacitances are counted into the dilution andwill be used as the base line for implementing Multiplier worst-caseamplification below.

The best-case Charge-sharing of GBL is Group 1 that has only one C_(GBL)capacitor, thus achieving the highest sensed GBL voltage V_(GBL) levelwithout any dilution with the rest of J−1 GBL capacitors in J−1 Groupsin each GBL column. As a result, Group 1 or even Group 2 in HiNAND arraycan be designed to send the highly sensed GBL voltage directly to thecorresponding SA 504 bypassing the Multiplier 502.

The input or the detecting node of Multiplier 502 is BLP node. One majoradvantage of this HiNAND2 design over conventional NAND design is thevoltage control of BIAS signal, which is coupled to gate of a 20V HVlong-channel NMOS transistor MN6, shown in FIG. 5A. In prior-art NANDdesign, the BIAS signals have to be well controlled to be 2.3V toprovide a stable 0.7V-1.0V GBL precharge-voltage due to its high Vtvalue. It also needs to provide another lower gate voltage for helpingthe discharge of GBL line and then provide another higher voltage tofully pass the Vdd to GBL line as Program-Inhibit voltage.

Since there is no need of GBL precharge in this HiNAND2 Read operation,a fine-tune 2.3V supply is not needed. Additionally, the discharge ofeach LBL line and its associated broken GBL line is nothing to do withBIAS. The BIAS signal is just Vdd, thus another HV voltage supply is notneeded either. The only needed voltage is Vread=6V to allow the fullVdd=1.8V passage from GBL from upper Groups with higher diluted, sensedV_(GBL) voltages.

In one embodiment of this HiNAND design, the preferred high V_(GBL)voltage is between 1.8V and Vss from Group 1, between 0.9V and Vss fromGroup 2, between 0.6V and Vss from Group 3, between 0.45V and Vss fromGroup 4, and between another gradually decreased value of 0.1125V(1.8V/16=0.1125V when reading from Group 16 if 16 dispersed WLs in 16dispersed Groups are selected) and Vss from Group 16. In worst case Readfrom Group J, the Multiplier 502 is required to amplify V_(GBL) to morethan 0.4V at OUTP node for a reliable sensing via Latch-type DRAM-likeSA 504.

In another embodiment, the precharged C_(SEG) voltage is V_(inhibit)which is set o be much higher than 1.8V. For example, ifV_(inhibit)=Vdd, then V_(GBL) voltage is 0.1125V (1.8V/16=0.1125V) whenreading from the Group 16 in worst case. If V_(inhibit)=7V, a biggerV_(GBL) voltage of ˜0.4375V is sensed at BLP node. Thus, Multiplier isnot needed at all.

Now, the Multiplier operation will be explained below in accordance withthe circuit shown in FIG. 5A. As shown, the input and output nodes ofthe Multiplier circuit 502 are denoted as BLP and OUTP respectively. Asmentioned above, the need of a Multiplier circuit for the HiNAND is anoption, all depending how many WLs can be selected for Read,Program-Verify and Erase-Verify operations. As a design thumb of rule,more WLs for simultaneous operations, then more the dilution of sensedV_(GBL) voltage so that Multiplier is more likely needed.

The amplified voltage at OUTP node is the outcome of the Multiplier 502after N-cycle amplification operations on input voltage detected at BLPnode. The amplification factor by the Multiplier is N, where N≧2 or anylarger integer number, depending on the required minimum ΔV_(GBL) valueand speed and area trade off for the reliable sensing of the DRAM-likeSA 504 connected to the OUTP node.

Referring to FIG. 5A, Multiplier 502 with a larger N for a largerV_(GBL) that will result in a larger silicon area and more sensingcycles of sample and hold on capacitors such as C[0]-C[N] are required.Practically, too many cycles of sample and hold operations onMultiplier's capacitor, C[N], to accomplish the final desired V_(GBL) isnot preferable for this fast multiple-WL Read and Verify operations.

Every capacitor of C[0] through C[N−1] is connected to two NMOS LV passtransistors. All capacitors of C[0] through C[N−1] are connected inseries from the top node of OUTP to the bottom node connected to IN[N].The value of each capacitor of C[0] through C[N−1] can be made the sameor different values. The type of capacitor is preferably made ofpoly1-poly2 and specially made metal capacitors without a Vt drop for afull coupling effect for this Multiplier's operation.

For example, the top (poly2) plate of the capacitor, C[1], is connectedto two LV NMOS transistors. One transistor is MN[1] with its left inputnode connected to a common input node BLP, its gate is tied to T[1], andits right output node connected to IN[1]. The other LV NMOS transistor,TP[1], with its drain node connected to IN[1], its source node connectedto Vss, and its gate tied to TP[1]. The bottom (poly1) plate of C[1] isconnected to the top (poly2) plate of C[2] not explicitly shown in FIG.5A. The top common sensing line of BLP is connected to a pull-up 20VNMOS device of MN6 with its gate tied to BIAS signal and its drain nodeis connected to each corresponding GBL, which is equivalent to beGBL_1[1:N] in HiNAND array.

Similarly, the top (poly2) plate of the last capacitor, C[N−1], isconnected to another two similar LV NMOS transistors. One transistor isMN[N−1] with its left input node connected to a common input node BLP,its gate tied to T[N−1] and its right output node connected to IN[N−1].The other LV NMOS transistor, TP[N−1] with its drain node connected toIN[N−1], its source node connected to Vss, and its gate tied to TP[N−1].

Similarly, the top plate of the first capacitor, C[0], is connected toanother LV NMOS transistor MN[0] with its left input node connected to acommon input node of BLP, its gate tied to T[0] and its right outputnode connected to OUTP of the Multiplier. The bottom plate of C[0] isconnected to IN[1]. The Multiplier operation for amplifying input at BLPto OUTP is divided into 4 steps. Step 1: SettingBIAS=Vdd+Vt+V_(margin)(0.5V) to allow the full passage of sensed voltageat GBL node with PGM=Vss to shut off the program path. Step 2: Firstsampling the V_(GBL) voltage at BLP node and store it at C[0] capacitorby setting the following conditions, T[0]≧Vdd+Vt, T[1]= . . . =T[N]=0V,TP[1]=Vdd, and T3=0V. Step 3: Repeat second sampling till N samplings ofV_(GBL) voltage at BLP node and store them to the respective capacitorsof C[1] to C[N−1] one by one serially by setting the followingconditions to boost the sensed voltage at OUTP node: T[0]=0V,T[1]≧Vdd+Vt, TP[1]=0V, TP[2]=Vdd, TP[2]=0V, and T3=0V. Step 4: One-shotT3 clock to latch the final sensed GBL voltage at Q[i] node of SA 504and one VREF voltage at the opposite node of QB[i] of SA 504 for NANDcell data evaluation. It needs T5 clock to further amplify the ΔVbetween Q[i] and QB[i] nodes.

The fully developed digital signal will be coupled to the gates of twoNMOS MN10 and MN11 transistors of the corresponding Program-Buffer 506.And later the sensed data will be transferred to each correspondingLatch (INV0 and INV1) of each Program Buffer 506.

For 1-bit Static PB shown in FIG. 5A, it contains one 1-bit Multiplier502, one 1-bit SA 504, one 1-bit Data Register 506 that furthercomprises one 1-bit static Program Buffer 550 and one 1-bit static DataBuffer 540. The 1-bit Static PB can only store 1-bit of sensed data at atime from HiNAND array or 1-bit desired programmed from I/O Controlcircuit 514.

The detailed operations of Data Buffer 550 and Data Buffer 240 in FIG.5A are illustrated below in accordance with the preferred Multiple-WLand All-GBL SLC operations.

SLC Data Buffer (DB) 550 includes one Data Latch (DL) made of INV0 andINV1 with one pair of D1 and D1B nodes. Referring to FIG. 5A again, toset and reset this DL, following bias conditions can be applied to: a)VFY with one-shot pulse when Q[i]=Vdd to set D1=Vdd, where Q[i] is oneof the input node of SA 504; b) RW_RES with one-shot pulse to setD1=Vdd; c) RWT_BK with one-shot pulse to set D1=Vss; d) LATP withone-shot pulse when Q[i]=Vdd to set D1=Vdd, where Q[i] is one of theinput node of SA; e) one-shot data loading when conditions of LOAD=Vddor Vread and Q[i]=LATP=RECALL=RW_RES=Vss.

The 1-bit data is sequentially loaded in corresponding one bit of DL inSLC Data Register 506 from I/O Control circuit 514 through Y-passcircuit 510. Additionally, prior to data-in loading, one-shot of RW_RESto set all D1=Vdd is required.

The final data in DL is subject to each loading data bit from I/O. TheD1 is kept to initial Vdd if the corresponding loaded data bit is “1”and D1 is set to Vss if the loaded data bit is “0.”

SLC data loading cycle of Multiple-WL Program operation is furtherillustrated below by referring to FIG. 5A. During the data-in loading,the required voltage polarity at GBL node is identical to D1 node. Ifthe data-in D1=1, that means the cell should be performedProgram-Inhibit scheme to keep at E-state, thus V_(GBL)=Vdd or Vdd-Vt.But when data-in D1=0, that means the NAND cell should be programmedtoward an A-state. As a result, the corresponding V_(GBL)=0V.

The 1-bit of the Program and Program-Inhibit data pattern per one WL issequentially supplied to each DL with PGM=Vss. The data loading isperformed sequentially in unit of Byte of 8 I/Os or words if 16 I/Os persystem clock along with the increment of Y-pass counter to select theright 8 GBLs per one system clock. For one largest physical WL size of128 KB of NAND today with 8 I/Os, it will take total 128K system clocksjust to complete one whole SLC data for one single whole physical WL.

Unlike conventional 1-WL Program, this preferred Multiple-WL Programneeds to quickly transfer one whole WL N-bit data to on-chip N-bitC_(SEG) capacitors once one whole WL data loading is completed. ThisN-bit DL loading to N-bit corresponding C_(SEG) capacitors or DynamicCache Registers at the designated areas in Group 1 can be done byone-shot pulse PGM clock (PGM≧Vdd) applied on the gates of N MN20transistors with enough time elapse associated with the right addresslogic to select the corresponding Dynamic Cache Registers. In this case,V_(BIAS)≧Vdd.

The program-data loading is to connect D1P to GBL through BLP. An INV2is needed to prevent each DL's data D1 from being corrupted when ahighly low capacitive node of D1 is connected to a highly capacitivenode of corresponding GBL and BLP.

For a case of 16-WL and All-BL simultaneous Program operation with alargest 128 KB per WL size, then totally 16×128K=2,048K system clocksare required to complete 16 WLs data transferring from I/Os to thedetonated C_(SEG) capacitors in preferred Group 1 in accordance withFIGS. 4A-4D. For example, DDR2-NAND with 5 ns clock cycle has twoloadings, then total 2,048K clock cycles will take 5,120 ms roughly.

Therefore, Multiple-WL Program data loading is serially performed fromI/Os to the selected N-bit C_(SEG) capacitors through N-bit SLC DataRegister and right address selection of the corresponding multiple N-bitC_(SEG) Dynamic Cache Registers.

Multiple-WL SLC Program-Verify operation can be also illustrated byreferring to FIG. 5A. The is an iterative data-out operation from oneselected WL at a time but the data and voltage polarity is oppositebetween D1 node and GBL node. For example, if GBL node is at 0V, thatmeans the verified cell passing the Program-Verify, thus it should beprevented from the subsequent program pulses. Thus D1 is set to Vdd,thus D1P=Vdd, and BLP=GBL≧Vdd-Vt to inhibit program. Conversely, if theverified V_(GBL)=Vdd, thus the cells' Vt not passing the verified Vtwith R1=0V for a SLC verification. Thus the D1B is set to Vdd butD1P=Vss, thus GBL is reset to Vss. The cells will get programmed.

This Program-Verify operation needs one full-cycle like Read operationto precharge all selected C_(SEG) or C_(GBL) capacitors with aV_(inhibit) voltage level initially and then discharged to Vss level orretaining the precharged V_(inhibit) level. The final settled voltagepatterns on C_(SEG) or C_(GBL) capacitors will be sensed and amplifiedby Multiplier 502 and SA 504. The details should be same as previousHiNAND Read operation. During this multiple-WL Program-Verify cycle, thefollowing bias conditions with LATP=RECALL=RW_RES=PGM=RW_RES=Vss are setto prevent the leakages from happening on two nodes D1 and D1B of eachDL.

Similarly during the Recall cycle, all N DIs are reset to D1=0V prior toRecall operation. Referring to FIG. 5A again, the Recall is performed tosense the stored voltages at C_(SEG) capacitors in Group 1. Thus, thisoperation is not intended to read any NAND cells in any WLs. Thisoperation is to sense the stored voltage in smaller N C_(SEG) capacitorsor larger N C_(GBL) capacitors in the corresponding Dynamic CacheRegisters per row and then restore into the Static Data Buffers in PB.As a result, the restored voltage back to D1 should be same phase as thevoltage at GBL. In other words, if V_(GBL)=0V, then D1=0V, then D1=0V toremain its initial state. If V_(GBL)=high and is amplified to a full Vddat Q[1] node of SA 504, then D1 is reset to Vdd by applying one-shot ofVFY signal to the gate of transistor MN17 to set D1B to Vss. Thus thestored program data patterns are successfully restored back into N DataRegisters 506.

FIG. 5B is a circuit diagram of multi-bit static PB circuit for HiNANDarray that allows to store e-bit NAND multiple-state page data forMultiple-WL and All-BL Simultaneous (MLC, TLC, XLC, . . . ) operationsaccording to an embodiment of the present invention. As shown, themultiple-bit static PB 600 includes one Multiplier 602, one multi-bit SA604, and one Data-Register 606 along with one Y-pass circuit 610, OneCache Register 612, one I/O Control 614, and multiple I/O [1:X] pins 622for J-WL and All-GBL Simultaneous SLC operations for both HiNAND1 andHiNAND2 arrays. The Data-Register 606 includes one e-bit Matching logiccircuit 630, one independent eData-Register, 340, and one sharedProgram-Buffer 650. For a MLC Program, e=2, for a TLC Program, e=3 andfor a XLC Program, then e=4. The e-bit Matching circuit, 630, is addedto the multiple-bit static PB 600 for this Multiple-WL and All-BLsimultaneous Program operation. Additionally, an on-chip Code-generatorcircuit 608 is added to the multiple-bit static PB 600. It generates eoutputs of CODE1 to CODEe. For example, e=4 for 4 MLC codes from 00 to11, e=8 for 8 TLC codes from 000 to 111, and e=16 for 16 XLC codes from0000 to 1111. The codes can be easily generated from an on-chipState-machine.

Basically, the detailed operations of Multiplier circuit 602 and SAcircuit 604 in FIG. 5B are identical to the counterparts of Multiplier502 and SA 504 in FIG. 5A, thus the descriptions are skipped here forsimplicity. The control of LATP signal in FIG. 5A has been replaced by areversed signal LAT to set the opposite leg of one latch made of INV2and INV3 in Data-Buffer 640 in FIG. 5B as oppose to latch made of INV0and INV1 in FIG. 5A.

Referring to FIG. 5B, similarly, the major function of Program-Buffer isto generate and store the Program and Program-Inhibit MLC/TLC/XLC datapatterns. When the read NAND MLC/TLC/XLC data matches the storedMCL/TLC/XLC data, then MTACH node is Vdd to turn on MN23 with acondition of setting I[i] and VFY to Vdd so that Q0B node is at Vss andBLP at Vdd to send the Vdd-Vt MLC program-inhibit voltage to thecorresponding GBL lines to prevent MLC over-program.

Prior to Multiple-WL simultaneous Program, one-shot of RW_RES is appliedto the gate of MN13 to set D1B node to Vss but D1 node to Vdd to allowan easier loading into DA made of INV2 and INV3 in Data-Buffer 340 ofeach data-in bit from 320 bus from I/O Control 614.

Basically, Multiple-WL and All-BL Read and Program-Verify operations ofthe present invention is more powerful and more flexible to allow bothRead and Program-Verify performed simultaneously on more than oneselected WLs from more than one selected Segments from more than oneGroups of the HiNAND. But there is only one N-bit PB connected toN×C_(GBL). The single PB and N C_(GBL) capacitors are designed to beshared by all selected WLs in the HiNAND array. This HiNAND2 with oneN-bit PB is referred as HiNAND2-1PB-N scheme.

In an embodiment, the above Multiple-WL & All-GBL Read andProgram-Verify operations are based on a evenly divided HiNAND2 arraywith 16 or less NAND Groups. In addition, the layout of a N-bit PB isbeing placed on top of HiNAND2 array with Group 1 at top and Group 16 atthe bottom and Group 2 to Group 15 placed in between in the graduallyincreasing order from top to the bottom. All N broken metal2 GBLs in 16Groups are laid out in such a way with N outputs connected to the topN-bit PB. Group 1 is the HiNAND group that is closest to the PB. Whenreading any single WL from Group 1 to the PB, it experiences the fastestand smaller RC delay of one C_(GBL) with zero M_(GBL) resistor.Conversely, when reading any page or WL from the bottom Group 16, itsuffers longest RC delay of 16 C_(GBL) capacitors and 15 M_(GBL)resistors. As a result for this preferred Multiple-WL and All-GBLscheme, the total broken GBL RC delays from the fastest Group 1 to theslowest Group 16 varies widely due to the widely uneven RCcharge-sharing nature in above HiNAND2 array layout arrangement that hasone full N-bit PB placed in top end of HiNAND2 array. This is named as aHiNAND2-1PB-N scheme.

In an alternative embodiment, a HiNAND2-2PB-N scheme has two identicalN-bit PBs with top N-bit PB being connected to the first N-bit GBL_1capacitors of Group 1 and bottom N-bit PB being connected to the lastN-bit GBL 16 capacitors of Group 16. In between, there are 14 brokencapacitors such as N-bit GBL_2 to N-bit GBL_(—) 15 as explained inprevious HiNAND2-1PB-N scheme with only one N-bit PB placed on the top.Other control signals such as LBLps lines, CSL lines, PRE lines andDIV-EN lines and SEG lines, the numbers of MLBLp and MLBLs transistorsremain the same without changes.

In this novel HiNAND architecture with two N-bit PBs, the Group 16 RCdelay read by the bottom N-bit PB will be same as the Group 1 read bytop N-bit PB in 1-cycle All-GBL Read as explained above. The N-bitdifferent data can be stored separately in both top and bottom N-bitPBs. As a result, the slowest read latency happens on the Group 8 andGroup 9. In this architecture, more evenly RC delay and powerconsumption is being achieved for this more powerful Multiple-WL andAll-BL read and program scheme.

In another alternative embodiment, a HiNAND2-2PB-N/2 scheme has twoidentical N/2-bit PBs with one top N/2-bit PB being connected to thefirst N/2-bit Odd/Even GBL_1 capacitors of Group 1 and the bottomN/2-bit PB being connected to the last N/2-bit Even/Odd GBL_16capacitors of Group 16. In between, there are similar 14 brokencapacitors such as N-bit GBL_1 to N-bit GBL_15 as explained in previousHiNAND2 array with only one N-bit PB placed on the top. Other controlsignals such as LBLps lines, CSL lines, PRE lines and DIV-EN lines andSEG lines, the numbers of MLBLp and MLBLs transistors are not changed.

In this novel HiNAND architecture with two N/2-bit PBs, the Group 16 RCdelay read by the bottom N/2-bit PB will be same as the Group 1 read bytop N/2-bit PB but in 2-cycle of ½-GBL read from same side of N/2-PB asexplained above. As a result, the slowest All-GBL read latency stillhappens on the Group 8 and Group 9. In this new architecture, it ispreferred to read one selected full WL page data from one end of PBbecause the true bottleneck of delay of reading one full WL is not the2-cycle or 1-cycle of charge-sharing delay. The different delay of1-cycle and 2-cycle of charge-sharing is less than 200 ns, which isnegligible.

The bottlenecks of read delays are C_(SEG) and C_(GBL) charge andDischarge delays of one full page or physical WL. For HiNAND2-2PB-N,HiNAND2-2PB-N/2, and HiNAND2-1PB-N scheme the data-pattern trapped inthe selected Blocks and determined by the corresponding PB is almostsame, regardless of one PB or two PB. Note, although one-side N-bit PBis being divided into two-side two N/2-bit PBs, the charge and dischargeoperations are still performed in one full physical WL or page of allabove HiNAND2 arrays.

As a result more evenly and flexible read latency arrangement and powerconsumption can be achieved for this more powerful Multiple-WL andAll-BL HiNAND Read and Program scheme.

In yet another alternative embodiment, simultaneous reading Multiple-WLand All-GBL data from one selected Block per Segment of multipleSegments within one NAND Group, particularly in top Group 1 or bottomGroup 16 for the structures of HiNAND2-1PB-N, HiNAND2-2PB-N/2, andHiNAND2-2PB-N scheme, are illustrated below in accordance with thecircuit shown in an embodiment of HiNAND2 array shown in FIG. 2B.

In a specific embodiment, the eight steps of Read operation described inearlier sections of the specification in accordance with FIG. 8 and FIG.9 are still applicable to the HiNAND2-1PB-N Multiple-WL and All-BL Readscheme based on Group 1 of HiNAND2 array circuit shown in FIG. 2B withn=1. In the embodiment, the HiNAND2-1PB-N scheme includes a) Total LSegments in Group 1, thus L C_(SEG) capacitors such as LBL_1_1 toLBL_1_L; b) K Blocks for each of the L Segments; c) Capacitance ratio ofC_(SEG)/C_(GBL) of about 1/16 to read one selected WL data in one of theSegment in Group 1 which is kept the same as the ratio arrangement toread one selected WL-data from Group 16 to the top PB for using a sameamplification factor of the same Multiplier; and d) The reducedprecharge current because only one C_(SEG) per Segment needs to beprecharged for this Multiple-WL and All-GBL Read operation. Total LC_(LBL) capacitors associated with L Segments need to be simultaneouslyprecharged for this simultaneous Multiple-WL and All-GBL Read operationwithin Group 1. L C_(SEG) capacitors includes LBL_1_1[1] to LBL_1_1[N]for Segment 1 to LBL_1_L[1] to LBL_1_L[N] for Segment L.

The first step of multiple-WL and All-GBL Read from Group 1 only is tosimultaneously predischarge the voltages of all C_(SEG) capacitors inSegment 1 such as LBL_1_1[1] to LBL_1_1[N] to all C_(SEG) capacitors inSegment L such as LBL_1_L[1] to LBL_1_L[N] respectively throughLBLps_1[1] to LBLps_1[L] lines simultaneously and separately in LSegments of Group 1 by setting the following biased conditions: a)PRE_1[1]= . . . =PRE_1[L]=Vd; b) LBLps_1[1]= . . . =LBLps_1[L]=Vss; c)SEG_1[1]=Vdd but SEG_1[2]= . . . =SEG_1[L]=Vss to predischarge N GBL_1to Vss; and d) DIV_EN[1]=Vss.

Note, setting SEG_1[2] to SEG_1[L]=Vdd can also help pre-dischargeC_(GBL) faster but would require more power consumption. It is preferredto use only one LBLps to discharge C_(GBL) in Group 1 by turning on oneSEG_1[1]=Vdd but keeps the rest of SEG_1[2]= . . . =SEG_1[L]=Vss.Setting) DIV_EN[1]=Vss is to isolate all capacitors of GBL_2[1] toGBL_2[N] in Group 2 from the discharging capacitors of GBL_1[1] toGBL_1[N] in Group 1. Other groups from Group 2 to Group 16 are atdon't-care state during this Group 1 Read operation. This pre-dischargestep can be completed within 100 ns. Thus this step is not thebottleneck of this preferred Read operation.

The second step of multiple-WL and All-GBL Read from Group 1 only is toprecharge all N selected local C_(SEG) capacitors per one Segment suchas LBL_1_1[1] to LBL_1_1[N] in Segment 1 to LBL_1_L[1] to LBL_1_L[N] inSegment L simultaneously. The precharged voltage is preferably set to beVdd (1.8V) by setting the following bias conditions: a) PRE_1[1]= . . .=PRE_1[L]=Vread=6V in one-shot pulse; b) LBLps_1[1]= . . .=LBLps_1[L]=Vdd=1.8V; c) SEG_1[1]=SEG_1[2]= . . . =SEG_1[L]=Vss; d)SSL[1]=Vdd and GSL[1]=Vss to prevent leakage to respective LBLps_1[1] toLBLps_1[L/2]; e) WL(selected)=V_(R), but WLs(unselected)=Vread=6V; andf) DIV_EN[1]=Vss to isolate the capacitors of GBL_2[1] to GBL_2[N] inGroup 2 from the discharging capacitors of GBL_1[1] to GBL_1[N] inGroup 1. Other groups from Group 2 to Group 16 are at don't-care statesduring this Group 1 Read. This precharge step can be completed within100 ns. Thus this step is not the bottleneck either of this preferredRead operation.

Now, the preferred precharge happens only on N shorter LBL metal1 lineswithin Group 1 not including N C_(SEG) capacitors in other Groups sothat only 1/J of broken C_(GBL) capacitance is subjected to theprecharging not the total C_(GBL) capacitance from all Groups as shownin previous Read operation (see FIG. 9 based on FIG. 2B). Thus theprecharge step in the Multiple-WL and All-GBL Read from Group 1 or Group2 consumes much less power but with much faster speed.

In order to make sure the number of Segments to be flexibly selected forRead in multiple Groups, one latch circuit per one Segment needs to beimplemented in each Group.

In addition to precharge the selected LBL capacitors, similarly theselected in the selected Segments in Group 1 are also preferablyprecharged to V_(R) WL Read voltage and the unselected WLs are appliedto a Vread voltage simultaneously to save total time delay of thissecond 1-cycle Multiple-WL and All-GBL Read operation. The Vread voltagetypically is set to be around 6V. The Vread voltage for unselected WLsis called a pass voltage.

As a result, the precharge time of the selected C_(SEG) and C_(GBL) canbe completed within 100 ns, which is very fast. But charging the passvoltage time for unselected WLs is much longer of few micro-seconds,thus in this BL and WL precharge cycle period, the delay in charging thepass voltage to unselected WLs is one of the key bottleneck.

The third step of multiple-WL and All-GBL Read from Group 1 only is todischarge the C_(SEG) capacitors on one or more selected WLs=V_(R). Thevoltages of all local trapped N C_(SEG) capacitors are simultaneouslyeither discharged to Vss or retained at 1.8V fully determined by thestored page data in one selected WL per Segment in Group 1.

For example, for a SLC Read, then the selected WL is set to V_(R)=0V,and 63 non-selected WLs are set to Vpass=6V. GSL[1]=Vread but SSL=Vdd.Part of the N C_(SEG) capacitors start to discharge from initial 1.8V toVss within a predetermined discharge time if the corresponding NAND cellVt=Vte<−0.7V, which is E-state. The remaining part of the N C_(SEG)capacitors retain its initial precharged voltage of 1.8V if thecorresponding NAND cells Vt>0, which is A-state.

Thus, after above steps of the Multiple-WL & All-BL Read operation ofthis HiNAND2 array, the selected Segments' LBL lines and the selectedGroups' broken GBL lines will trap respective either Vss or 1.8Vvoltages in accordance with the stored NAND data pattern on the selectedWL of the selected Block in the selected Segment in the selected Group(Group 1) of this HiNAND array. After J-WL & All-BL Read, either 1.8V orVss will be stored isolately or separately in all N×LBL_1 to N×LBL_Jcapacitors in accordance with the stored data in multiple WLs when allDIV_EN[1]= . . . =DIV_EN[J−1]=Vss. Note the discharge time of eachsmaller C_(SEG) capacitor is about J-fold (e.g, J=16) faster than todischarge each bigger C_(GBL) capacitor performed in a Read operationwith the same 64-NAND cell string (see FIG. 9 in association with FIG.2B).

The fourth step of multiple-WL and All-GBL Read from Group 1 only is toperform a charge-sharing cycle between each C_(SEG) capacitor and eachC_(GBL) capacitor in Group 1 for the multiple-WL & All-GBL Readoperation.

In order to avoid data contention in each C_(SEG) and each C_(GBL), thedata in each C_(SEG) will be transferred to the common C_(GBL) one byone from different Segments in Group 1. As well arranged above, thecapacitance ratio C_(SEG)/C_(GBL)<1/16, thus the amplification ofMultiplier can be kept the same as previous read from all Groups. Thedetails would be skipped here for description simplicity.

In this case the charge-sharing of different Segments with one commonC_(GBL) is fully random in nature. Since charge-sharing takes a veryshort time, thus this step is not the bottleneck of this preferredMultiple-WL and All-GBL Read operation from the same Group 1. The reststeps of multiple-WL and All-GBL Read from Group 1 only aresubstantially the same as ones shown in FIG. 8 and FIG. 9 for readingmultiple WLs from Multiple Groups, thus the detailed descriptions arealso skipped here for simplicity.

Note, the above two kinds of Multiple-WL and All-GBL Read operationsshow the first example is to read multiple WLs from Multiple Groups andthe second example is to show to read multiple-WL from Group 1 forHiNAND2-1PB and from Group 16 as well as for HiNAND2-2PB-N orHiNAND2-2PB-N/2, etc.

Other combinations of Multiple-WL and All-GBL Read operations arepossible. For example, read Multiple WLs from all Groups along with readMultiple WLs from Group 1 and Group 2 and even from Group 2 and Group 15as well by properly arranging the capacitance ratio of C_(SEG)/C_(GBL).All above mentioned or non-mentioned Multiple-WL and All-GBL read shouldbe all covered by this invention without a limitation, regardless of 2Dor 3D NAND flash.

In operating the Multiple-WL and All-BL Read, the storages differenceswould make the read flow different. In an example of Multiple-WL andAll-BL SLC Read, each WL stores the SLC 2-state data. Therefore, allselected Blocks are applied with same set of biased voltages for oneselected WL=0V and 63 unselected WLs=Vread, SSL=Vdd and GSL=Vdd. As aresult, the discharge of precharged 1.8V or higher V_(inhibit) voltageare performed simultaneously on all the selected WLs in the selectedBlocks in same selected Segments in different Groups or in the selectedBlocks in different Segments but same Group 1 or Group 16.

Since the selected LBL capacitors of the selected Segments are eitherdischarged or retain precharged charges simultaneously by the selectedWL, the read data of selected multiple WLs will be ready at the sametime and the data patterns are stored in the corresponding C_(SEG)capacitors. Later, each WL's C_(SEG) data is serially loaded from theselected Blocks into each corresponding Cache memories of the PB.

In an example, the PB preferably has at least 2 rows of N-bit Cachememories, Cache1 and Cache2, to allow proper handling of reading J-WLdata (J=16) either from same Segments of 16 different Groups or from 16different Segments within a same Group. The two Cache memories arepreferably operating in pipe-line manner and are controlled by on-chipState-machine.

The N-bit Cache1 memory is directly connected to the outputs of a N-bitSA. The inputs of the N-bit Cache2 are connected to the outputs of theN-bit of Cache1. After the completion of simultaneous dischargingoperations of 16-WL read, any one of the 16-WL can be selected to betransferred to the Cache1. Once the loading of a first WL data iscompleted, the second WL data is transferred to Cache1 by therising-edge of clock, but the contents of the first WL data istransferred to from cache1 to Cache2 by a falling-edge of a clock toavoid the data contention.

Thus, total 16-WL and All-GBL SLC data can be sequentially read out oneby one into Cache1 and then sent to I/O to the off-chip Flash controllerthrough Cache2 in a fast pipeline fashion with only requirement of asmall PB size. The number J of WLs being associated with a simultaneousMulti-WL Read and number K of WLs being associated with a simultaneousMulti-WL Program can be different. For a Read charge-sharing concern,the J is kept ≦16 but K can be larger than J because multiple-WLsimultaneous Program do not have charge-sharing steps. Thus the thumb ofrule in HiNAND2 array is K>J. K even can be set to be like K=2×J or 4×J,etc.

In an example of Multiple-WL and All-BL 4-state MLC for 16 WLssimultaneous Read, there are one erased-state of E state and threeprogrammed states of A, B and C with the stored Vt values, Verifyvalues, and Reference values in accordance with the drawings shown inFIG. 1C. The similar approach can be extended into 8-state TLC and16-state XLC Read.

The SLC Read is like the R1 Read (see FIG. 1C), which V_(R1)=0V isapplied to the all 16 selected WLs. The E-state data of 16 WLs are readyand stored on each corresponding broken C_(GBL) capacitance and C_(SEG)capacitance if 16 WLs are located in 16 different Groups. Now, thereading of these 16 WLs will be performed sequentially from Group 1 toGroup 16 if HiNAND2-1PB-N is used.

In one option, the first-WL data in Group 1 is transferred to the N-bitCache1. Then, the same location (WL address) of the second-WL indifferent Segment is also read out and transferred to same PB bufferwith the first-WL data being transferred to Cache2. All the subsequent14 WLs' data would be serially transferred to Cache1 in pipeline mannerduring the previous WL data being transmitted to I/O. Thus, after 16clocks, total 16 SLC data are being transferred to Flash controller forsubsequence calculation of MLC.

Next, a higher V_(R2) is applied to all 16 WLs for data evaluation toget A-state data (see FIG. 1C). Again, 16 WLs of A-state data would beserially sent out to Flash controller for subsequent MLC datacalculation. Before sending out these 16-WL data, a 4-bit divided-by-2D-Flipflop can be used to encode these 16 data per 16 WLs. Any 0-databeing sensed in each State will clock the state-advance of this 4-bitFlipflop. Any 1-data would not clock into the next level. As a result,the 16-WL data per State can be converted into 4-bit MLC data. Thus,only 4×16=64 clocks as the conventional MLC Read of 16-WL data can beachieved.

In another embodiment, this Multiple-WL and All-GBL SLC Read operationcan be extended into preferred Multiple-WL and All-GBL Program andProgram-Verify operations under the same HiNAND2 array circuit. Beforeperforming any HiNAND2 Program operation, the flash cells have to beerased to a negative E-state first. In prior art, the Erase operation isperformed in unit of a Block. The Block size can be 1 Mb up to 4 Mb,depending on the specs and applications. And the typical Block erasetime ranges from 2 ms to 5 ms.

A typical Block includes 64 NAND-cell Strings. That means a String of aBlock is comprised of 64 WLs. The Block Erase operation issimultaneously performed on all 64 WLs by grounding all 64 WLs such asV_(WL1)=V_(WL2)= . . . =V_(WL64) to Vss with a common TPW being set to20V. All these 64 WLs are in the one physical String and one physicalBlock. It is referred as Consolidated Block.

But to simultaneously program these 64 WLs in a Consolidated Block witha size of 8 KB per WL in one physical Block like above Erase operationis totally impossible under the conventional NAND architecture in thepast 25 years.

Unlike the conventional NAND with Consolidated Blocks, these 64 WLs arepreferably dispersed in 64 different Blocks as one WL per Block with asame cell-String location within the preferred HiNAND2 arrayarchitecture. This kind of Block is referred as Dispersed Block of thepresent invention. Accordingly, the conventional 64-WL Erase operationin one physically Consolidated Block is preferably changed tosimultaneously erase 1-WL per Dispersed Block within a scheme of 64-WLin 64 physical Blocks. As a result, both Erase and Program operationscan be preferably performed on 1-WL per Block basis but simultaneouslyon 64 WLs respectively in 64 Blocks. Therefore, a 64-fold program-timereduction for one physical page can be achieved with thisDispersed-Block structure.

An embodiment of the present invention using higher V_(inhibit) voltageto replace Vdd in a non-SBPI method is also adopted here for achieve asuperior program-inhibit (PI) function but along with a new set of WLbiased conditions. The reason of using V_(inhibit) voltage and Vss forProgram-Inhibit and Program is to get a higher initial Inhibit voltageof Vpass-Vt in the NAND channels of unselected programmed cells. Theconventional SBPI method uses Vdd as low as 1.8V. The V_(inhibit)˜7Vwould have about 5.2V higher initial voltage at the unselected LBLlines, which is passed to the flash channels of unselected programmedcells. By applying Vpass=10V to those unselected WLs with correspondingNAND cells at the highest programmed Vt=5V (For state C in MLC cell),the NAND channel' voltage is about 10V−5V=5V, which is still much higherthan Vdd prior to ramping the selected WL's gate to Vpgm of 20V.Additionally, this preferred Program scheme allows for one random-WLprogram per Dispersed Block, thus all NAND cells in any WLs can beselected for Program along with the remaining WLs with proper biasedvoltages (see Table 6 below).

Due to WL-WL coupling effect, the channel voltage of unselected programcells can still be boosted from initial 5V to about 10V. Thus, the finalchannel PI voltage is much higher than conventional NAND to have asuperior PI performance. For example, it is much less affected by, atthe worst-case scenario, 0V channels presented on both adjacent BLs of aprogrammed cell.

Again, referring to FIG. 2B, as the V_(inhibit) voltage is coupled fromonly one selected LBLps power line through the selected N MLBLs and N MStransistors by setting gate signals of PRE=SSL toV_(inhibit)+Vdd+ΔV_(margin) and setting NAND cells' gate to Vpass=10V onthe unprogrammed WLn+1 (up to WL64) to reach the NAND cells' channels inthe selected WLn. Note: the order of WLs are defined from the String topto bottom such as WL1, WL2, WLn−1, WLn, WLn+1, WL63, WL64 for a 64-cellNAND String. The selected WL is denoted as WLn. The unprogrammed WLs areWLn+1 up to WL64 and the programmed WLs are from WL1 to WLn−1.

TABLE 6 HiNAND2 LBL LBL operation WL₁ WL_(n−2) WL_(n−1) WL_(n) WL_(n+1)WL₆₄ TPW Block # Select unselect WL Vdd Vdd V_(pass) V_(pgm) V_(pass)V_(pass) 0 V 1-64   0 V 7 V Program voltage WL Erase F F F 0 V F F 20 V 1-64 F F voltage WL Read V_(read) V_(read) V_(read) V_(R) V_(read)V_(read) 0 V 1-64 1.8 V 0 V voltage Note: Vread = 6 V, Vpgm = 15 V-25 V,Vpass = 10 V, F = Floating, V_(R) = Read WL MLC voltages.

In addition, all SEG, PRE, SSL, GSL, CSL, LBLps, DIV_EN[J] are left atfloating to avoid the gate-oxide breakdown due to the common bulk ofTPW=20V. All NMOS select transistors (which are made of same devices)MLBLp, MS, MG, and MLBLs are configured to sustain the preferred PIoperation with higher V_(inhibit) voltage.

In the conventional NAND array architecture, if V_(inhibit) voltage iscoupled directly from GBL lines, the program-inhibit current consumptionis too high. But in this preferred 2-level BL-Hierarchical HiNAND2structure, the V_(inhibit) voltage is generated from a centralV_(inhibit) pump circuit and is only coupled to 16 selected LBLpshorizontal power lines on a basis of one LBLps line per Dispersed Block.Thus, the capacitances of these 16 LBLps lines are much smaller so thatthe power consumption to couple the V_(inhibit) voltage to NAND cellchannels is drastically reduced as compared to the required high currentconsumed in each long and heavy GBL capacitor when using Vdd in PIoperation.

The program Vpass gate-disturbances in the selected String for eitherthe case of using Consolidated Block or the case of using DispersedBlock are the same. Therefore, the advantage of low-power consumption ofusing V_(inhibit) scheme for simultaneous Multiple-WL and All-GBLProgram and Erase operations is not achieved at the expense of NANDmemory reliability, power, and silicon area.

Two embodiments of Block Erase in this HiNAND2 array are illustratedbelow. In a specific embodiment, total 64 WLs are arranged in oneHiNAND2 physical Consolidated-Block so that the Erase operation isexecuted in unit of 64 WLs in one physical Consolidated-Blocksimultaneously but the Program operation can only be performed in 1-WLper Block base. The saving of WL Program cannot be benefited from thisscheme.

In another specific embodiment, total 64 WLs are arranged in 64 HiNAND2Dispersed-Blocks so that both the Erase operation and the Programoperation can be executed in unit of 64 WLs simultaneously in theDispersed-Block scheme, resulting in a big saving in Block's program andread time.

In this HiAND2 Program operation, there are at least two preferred PIschemes: Case1) using Vdd as an V_(inhibit) coupled from N long brokenGBL lines and PB and Case2) using 7V as V_(inhibit) coupled from N shortLBL lines and only 16 LBLps lines coupled from one V_(inhibit) pumpcircuit. The values of N can be 8 KB=8,192 or 16 KB=16,384 for onephysical page or WL in HiNAND2 (same as conventional NAND) array.

Case1: Each WL data of Vss-program and Vdd-inhibit voltages are coupleddirectly from a N-bit PB to one selected N-bit Block at a time. TheseVss and Vdd voltages are passed to the selected channels through Nselected broken GBLs, through N selected MLBLp transistors in on-stateto N broken LBL lines and then to N Selected NAND Strings through Nfirst String-select transistors MS in on-state and N secondString-select transistor MG in off-state to prevent the String leakage.All this Vdd-inhibit and Vss programmed voltages are then latched ortrapped in the selected N C_(SEG) capacitors in the selected Segment andGroup in accordance with the WL data stored in the N-bit PB. After thismedium C_(SEG) capacitors are precharged with one-shot of Vdd-inhibitand Vss, the N gates of LBL-select transistors MLBLp are then being shutoff by setting SEG signal to Vss to trap Vdd-inhibit and Vss. Thisprecharged process takes time less than 200 ns to 3 μs, depending on theBlock location or distance of the selected broken C_(GBL) from the PB.

After the first trapping of Vdd-inhibit voltage in the first C_(SEG)capacitor of the first selected WL and the selected Block, the remaining63 C_(SEG) capacitors for 63 WL in 63 dispersed Blocks in the 63dispersed Segments either in one Group or different Groups are then totrap the similar Vdd-inhibit and Vss voltages in 63 V_(inhibit)precharge cycles. Since the conventional NAND architecture does not havethis 2-level broken-BL hierarchical structure array, thus the trappingof multiple pages of V_(inhibit) and Vss voltages cannot be realized.Conversely, multiple trappings of V_(inhibit) and Vss voltages can berealized in this HiNAND2 array, thus the Multiple-WL and All-BL Programscheme can be easily executed to save 64-fold reduction in program timeif each String includes M=64 WLs.

Case2: In this case, all selected C_(SEG) capacitors are precharged with7V-inhibit voltage initially by coupling the selected 64 LBLps lines(respectively associated with 64 Segments in dispersed Groups) to 7Vwith PRE being set to 7V+Vt+V_(margin), where V_(margin)˜0.5V. For thiscase, PRE signal is at Vpass˜10V.

The precharge cycle is similar for charging N broken C_(GBL) capacitorswith Vdd-inhibit and Vss voltages as in Case1 which are coupled from aN-bit PB in accordance with the stored WL-data pattern. Then SEG signalis switched from Vss to Vdd to turn on MLBLp transistors to connect eachbroken C_(GBL) capacitor to each corresponding C_(SEG) capacitor that isfilled with the precharged 7V-inhibit initially. As a result, thevoltages of LBL capacitors will be selectively discharged to either Vssor retained to 7V-inhibit voltage according to V_(GBL)=Vss andV_(GBL)=Vdd from the PB respectively through transistors MLBLp set toOn-state.

In other words, both Case1 and Case2 need the Vdd-inhibit andVss-program voltages coupled from the common N-bit PB. But in Case1, no7V-inhibit voltage is coupled to all C_(SEG) capacitors prior to Programoperation. But in Case2, precharging 7V-inhibit voltage to all selected16 C_(SEG) capacitors are required for a superior PI and Programoperations.

In conventional NAND SLC one page (1-WL) Program, it takes about 250 μs.For 64-WL Program in a Consolidated-Block, it takes 250 μs×64=16 ms. Forthis preferred Multiple-WL and All-BL simultaneous SLC Program in 64Dispersed Block, it only needs 250 μs. This is a big saving in NANDProgram throughput.

This Multiple-WL and All-BL SLC Program scheme can be similarly appliedfor a MLC or TLC, even XLC Program to save the program time. Regardlessof Case1 or Case2 program, the N-bit PB is a same LV PB as theconventional NAND.

In principle, the total numbers of WLs to be programmed of the presentinvention are subject to at least following factors: 1) P/N junctionleakages, 2) operating temperature, 3) precharged V_(inhibit) voltages,4) the length or value of each C_(SEG) capacitance and 5) the number ofCaches in a PB.

Firstly, the total numbers of WLs to be programmed is determined by howlong the trapped V_(inhibit) voltage (7V or Vdd) can last duo to thejunction leakages of P/N source/drain areas of one transistor of MLBLp,one transistor of MS/MG, one transistor of MLBLp and 64 transistors ofNAND cells, MC, per C_(LBL) capacitor. Since 64 WLs are beingsimultaneously programmed in 250 μs per SLC, thus retaining all 64trapped V_(inhibit) voltages in 250 μs should not be a bottleneck ofprogram time. The longest time is the 64-WL data loading into andtrapped in the 64 N×C_(LBL) capacitors.

For example, for 2.5 ns/Byte DDR2 transmitted time and 8 KB page size,the total 64-WL loading time would be 2.5 ns×8K=20 μs. Then total 64-WLdata needs 20 μs×64=1.28 ms. This time lapse should be okay for thisVdd−V_(inhibit) and 0.1 pf per C_(LBL) capacitor. If there is a concernto retain V_(inhibit) within a 1.28 ms time lapse, then 2 cycles of two32-WL or 4 cycles of 16-WL Program can be used instead. As a result,even a 16-WL and All-GBL simultaneous Program is still a great saving inprogram time.

Secondly, the P/N junction leakage is highly depended on operatingtemperature. In particular, the higher operating temperature is, thehigher P/N junction leakage. Thirdly, the higher precharged V_(inhibit)voltage is, the longer retaining time for part of C_(LBL) capacitors. Inpractice, the highest V_(inhibit) voltage is set to be around 7V.Additionally, the length or value of each C_(LBL) capacitance is anotherdetermination factor for the number of WLs during simultaneous Programoperation. Furthermore, the number of Caches in a PB also affects thedetermination of the total number of WLs to be programmedsimultaneously.

Are 64 Cache memories per PB required to store 64-WL data and theirassociated addresses for a 64-WL simultaneous program? Practically, forprogramming 64-WL to have 64 Cache per PB is not economic. It is desiredto determine an optimal number of Cache memory for more flexiblehandling of on-chip Program-Verification of MLC or TLC Programoperation. One option is that the multiple-WL data is preferably loadedinto a 4-Cache memory serially from NAND 8×I/Os in a pipeline manner.Therefore, no multiple Registers or Caches to store all K-WL data isrequired for this HiNAND2's architecture design. In other words, underthe preferred condition that the number of Registers or Caches issmaller than K, for example, ½ K or ¼ K, etc.

FIG. 6A is a diagram showing a set of SLC Read timing waveforms forMultiple-WL and All-GBL simultaneous Read operation with a preferred setof initial biased conditions in accordance with the 1-bit static PBcircuit shown in FIG. 5A of both HiNAND1 and HiNAND2 arrays according toan embodiment of the present invention. As shown, the control signalsRECALL, PGM, LOAD, and VFY are set to 0V as initial biased conditions inaccordance with the PB circuit shown in FIG. 5A. Since SLC Data Registerhas 4 paths of 4 operations to set the digital value D1 of one Latchcomprising INV0 and INV1, so D1 is set to 0 when WAT_BK is subjected toone-shot pulse of Vdd; D1 is also set to 0 when LATO is subjected toone-shot pulse of Vdd; D1 is set to 1 when signal VFY is subjected toone-shot pulse of Vdd and Q[i] is coupled to Vdd; D1=1 when RW_RESsignal is subjected to one-shot pulse of Vdd.

As shown in FIG. 6A, the SLC Read Timing Waveforms start from twoundistinguished SLC states such as the erased E-state and the programmedA-state with one Latch's output D1 node reset to Vdd as an E-state in aProgram-Buffer along with the Selected WL voltage set to a value ofV_(R1) initially. For those selected NAND cells storing E-state, thecorresponding GBL capacitor voltage would be discharged to Vss to flipthe Latch's D1 from Vdd to Vss. For those selected NAND cells storingA-state, the corresponding GBL capacitors' voltage would be retainedafter charge-sharing and then amplified by the Multiplier to retainLatch's D1=Vdd, thus the stored state is A-state. Once the firstselected WL data is successfully distinguished, the page data would besent to I/O pins through I/O Control circuit. Subsequently, theremaining second to J WL data would be read out and evaluated each WLone-by-one and then sent out to I/O in a pipeline manner.

FIG. 6B is a diagram showing a set of Sample/Hold Multiple-WL SLC PGMpatterns timing waveforms in accordance with the 1-bit static PB circuitshown in FIG. 5A of both HiNAND1 and HiNAND2 arrays according to anembodiment of the present invention. as shown, the initial biasedconditions includes setting T3B signal at Vdd and setting RECALL, LATP,RES signals at 0V in accordance with the PB circuit shown in FIG. 5A forthe preferred Multiple-WL and All-GBL simultaneous Program operation.

As shown in FIG. 6B, the Multiple-WL SLC data are serially loaded intoand stored at those well-planned N-bit broken metal1 LBL capacitors inthe selected Segments, Groups of HiNAND2 array. Since the S/H functionis to load multiple-WL data into SLC Data Register within a Programoperation rather than a Program-Verify operation, the VFY signal is setto 0V. Additionally, it is not within a Read operation either, thus T3Bsignal must be set to Vdd. Again, it is rather than a Recall operation,thus RECALL signal must be set to 0V. In particular, the multiple-WLdata is serially loaded in to SLC Data Register in unit of Byte if I/Onumber is eight (8) or in unit of Word if I/O number is sixteen (16).

For storing J-WLs SLC data in the designated array areas of the brokenmetal1 LBL capacitors, totally J preferred rows of LBL capacitors nearthe PB are required. During J-WL Program-Verify operation, a Recalloperation to restore the Program SLC data pattern in HiNAND array to SLCData-Register 506 in the PB 500 (see FIG. 5A) is performed sequentiallyin a predetermined order from one-WL by J-WL to save the silicon area ofJ−1 Data Register.

Next, the WL-data loading into Data Register 506 (see FIG. 5A) startswith a one-shot pulse of RW_RES to reset D1=Vdd initially. The first SLCWL-data would be serially loaded into Data Register 506 in PB fromexternal I/Os 522 in unit of Byte as an example. Then for transferringN-bit of a large WL size of 16 KB, it will take 16K times to fill upwhole page of one WL SLC data. After 16 KB one WL SLC data beingsuccessfully loaded into N-bit Data Register 506 through bus 520 andY-pass 510, then the whole 16 KB data in the Data Register 506 via BLPline would be stored in the corresponding designed N-bit broken metal1GBL or metal1 LBL capacitors by one-shot of PGM clock. This one page orone row of LBL or GBL capacitors is termed as Dynamic Cache in HiNANDarray. For data bit=1, then the corresponding LBL or GBL capacitor wouldstore Vdd voltage, while data bit=0, then the corresponding LBL or GBLcapacitor would store Vss=0V voltage accordingly.

FIG. 6C is a diagram showing a set of set biased conditions ofMultiple-WL and All-GBL SLC simultaneous PGM timing waveforms inaccordance with the 1-bit static PB circuit shown in FIG. 5A. As shown,the biased conditions include setting signals LOAD and LATP to 0V inaccordance with the PB circuit 500 in FIG. 5A. This preferred set ofMultiple-WL SLC Program waveforms should be performed along with theassociated S/H waveforms shown in FIG. 6B.

Since this is the preferred S/H operation in Program operation to loadWL-data into SLC Data Register 506 (see FIG. 5A), rather thanProgram-Verify thus VFY=0V, rather than Read, thus T3B=Vdd, and ratherthan Recall, thus RECALL=0V. The data is serially loaded in to SLC DataRegister 506 in unit of Byte if I/O number is eight (8) or in unit ofWord if I/O number is sixteen (16).

FIG. 6D is a flow chart showing a method for the preferred Multiple-WLand All-GBL SLC simultaneous Program operation in accordance with thepreferred PB circuit shown in FIG. 5A. As shown, the method forperforming a SLC Multiple-WL and All-BL Program operation for both 2Dand 3D HiNAND2 arrays starts from loading the 1-WL or 1-page SLC datafrom external I/Os sequentially into N-bit Data Register (step 710).Once a whole page of N-bit data is ready in Data register, then wholeone-WL SLC data is then being transferred to N-bit Selected LBLcapacitors as termed as Dynamic Caches in step 712.

Total WLs' SLC data are checked if all of them being successfullytransferred to the multiple designated N-bit Dynamic Caches and StaticCache as shown in step 714. If the check indicates that all of WLs' SLCdata have been successfully transferred to the multiple designated N-bitDynamic Caches and Static Cache, then the Multiple-WL Program operationis activated in step 718. If not, then the above loading is continuedsequentially by increasing the page counter to next page address in step716.

Once the Program operation is finished after one iterative programpulse, then the next Multiple-WL Program-Verify operation would beinitiated as shown in step 722. But prior-to this Program-Verifyoperation, a Recall operation is performed at step 720 to restoremultiple-WL N-bit program data from Dynamic Cache or LBL capacitors backto the corresponding bits of one Static PB which is shared bymultiple-WL SLC data. Thus, the Recall is performed on one-WL by one-WLbasis sequentially.

During each WL data Program-Verify operation, those bits passing theProgram-Verify in one selected WL have to be set a V_(inhibit) voltageon the selected GBLs and transferred to selected LBL dynamic cache inparallel at step 724. The next WL data is moved to be subjected to thenext Program-Verify and is checked to see if all multiple-WL programmeddata being checked at step 726. If not, then move to next iterativeprogram cycle by increasing Vpgm by ΔVpgm on multiple WLssimultaneously. And then the next iterative program pulse is issuedagain at step 728.

The Program and Program-Verify iterative operations on all selectedmultiple WLs will be continued and checked. Once all multiple-WL databeing programmed passing the verification of desired data at step 730,and the Program and Program-Verify iterative operations will be stoppedat step 732.

FIG. 7A is a diagram showing a set of MLC Read timing waveforms forperforming the preferred Multiple-WL and All-GBL MLC simultaneous Readoperation in accordance with the multi-bit static PB circuit shown inFIG. 5B of both HiNAND1 and HiNAND2 arrays according to an embodiment ofthe present invention. As shown, the timing waveforms start from initialsetting E-state with two bits of CODE1 and CODE2 generated from on-chipCode generator and rolling from E-state, A-state, B-state, and C-statefor comparison against to two bits per NAND cell read from multipleselected WLs. The PB circuit is configured for MLC Read operation bydisabling Program and Program-Verify functions by setting controlsignals of VFY, PGM, LOAD, PGM_DIS, to 0V and setting signals RECALL1 toRECALLe, L2A1 to L2Ae, and PGM_EN to 0V, and also by setting RW_RES to0V, etc.

The data comparison starts first, by applying one-shot RES signal, fromthe preferred lowest level of E-state to A-state to B-state and thenC-state by applying the same step-rising voltages on multiple selectedWLs with V_(R1) (0V) to differentiate A-state from E-state, V_(R2) todifferentiate B-state from A-state and V_(R3) to differentiate the lastC-state from B-state.

Once the data is matched, the data would be locked into thecorresponding Data Buffer upon each rising-edge of T7 clock that willsequentially set LAT signals of corresponding Data Registers. The T3 andT5 are the signals used by each DRAM-like Latch-type SA 304 shown inFIG. 5B.

FIG. 7B is a diagram showing a set of Sample/Hold Multiple-WL PGMpatterns timing waveforms for the preferred Multiple-WL and All-GBL MLCsimultaneous Program Patterns operation in accordance with the multi-bitstatic PB circuit shown in FIG. 5B. As shown, the timing waveforms startfrom first setting all DLs to initial E-state by applying one-shot pulseof RW_RES. Then the external Multiple-WL program data are sequentiallyloaded into the static on-chip Data Cache in unit of byte if 8 I/Os NANDis used or in unit of Word if 16 I/Os NAND is used through I/O controlcircuit and system clocks.

First, the whole WL Word or Byte data are sequentially clocked by aplurality of LOAD clocks' rising edge. Totally, 2 N-bit MLC data per oneWL are loaded into 3 N-bit static Data Cache. After that, L2A1 and L2A2clocks are sent to load two corresponding C_(SEG) capacitors in multipleSegments in one Consolidated HiNAND Group or to one Segment per multipleDispersed HiNAND Groups as explained previously in FIGS. 4A-4D.

Since the storage data is MLC type, it just needs two clocks of L2A1 andL2A2. If the storage data is TLC type, then it needs three L2A1, L2A2and L2A3 signals to complete 3-bit TLC loading into 3 N-bit Data CacheRegisters. Note, in the circuit of Data Buffer of FIG. 5B, the two MLCoutputs are shorted at OUTP node through two MN15 transistors MSB andLSB bits of Data Buffer. That is why two separate clocks are needed toavoid data contention on OUTP node if 2-bit of MLC data per GBL line issent.

Once all MLC programmed data are fully loaded into 2 N-bit Data-Buffer,then 2 MLC bits have to serially loaded into the different C_(SEG)capacitors in predetermined addresses through only one shared GBL andone BLP line. Thus it needs to be loaded by two clocks of L2A1 and L2A2with BIAS≧Vdd for passing the MSB and LSB WL data into the correspondingC_(SEG) Dynamic Cache Registers, which actually are capacitors in HiNANDdesignated areas with the input of Multiplier 602 being disconnected.

But the Program and Program-Inhibit pattern has to be generated per one2-bit MLC data before Multiple-WL Program being executed. This can bedone by using a circuit of MN24, MN25, . . . , MN30 and MN6 with gatetied to PGM_DIS. For MLC, only D1 and D2 are required. For TLC, D1, D2and D3 are required to be at Vdd to reset Q0B to Vss so that BLP is setto Vdd to prohibit further program to avoid over-programming. Otherwise,unmatched MLC data would set BLP and GBL to Vss to allow the nextprogram pulse to increase Vt from E-state to A-state. Initially BLP andGBL are set to be 0V for programming by applying one-shot pulse to resetsignal PGM-EN to set Q0 at Vss but Q0B at Vdd, and set BLP to Vss at theoutput of INV8. Once matched, then MATCH is set to Vdd to reset Q0B atVss again so that BLP is at Vdd to provide the Vdd-Inhibit GBL voltagefor those matched MLC cells.

Once Program and Program-Inhibit of N-bit MLC is ready per wholeselected Multiple WLs, then the Program operation is initiated.

FIG. 7C is a diagram showing a set of biased conditions of Multiple-WLand All-GBL MLC simultaneous PGM timing waveforms in accordance with thepreferred PB circuit shown in FIG. 5B. Similar timing waveforms can beextended to TLC and XLC simultaneous Program operation. As shown, thetiming waveforms include the HiNAND2 array's major control signals suchas SEL, WL, RES, T3B, VFY, RW_RES, RECALL1, RECALL2, PGM, PGM_EN,PGM_DIS, L2A1, L2A2, Q0 of three WLs, etc. The selected multiple WLs areapplied with same step-rising Vpgm on the same address of multiple WLs.Unlike the conventional NAND Program, the Vpgm only applied to only oneselected WL, the HiNAND Program operation can be performed simultaneouson one and more selected WLs to cut the total program time.

One major difference is that there are more than one WL Program-Verifyoperations are performed between two successive program pulses. In afirst step, the initial one 2-bit E-state code of a MLC cell aregenerated on CODE1 and CODE bits to two DLs in two Data-Buffers 640 inFIG. 5B. And two outputs of D1 and D2 are coupled to the gates of MN24and MN25 with D1 and D2 being set to Vdd in the beginning of programcycle when one-shot clock of RW_RES is applied to the gate of MN13.Besides, SA and Latch of INV4 and INV5 are reset by one common signal ofRES. As a result, initially, both IB[i] and Q[i] are at Vss and D1 andD2 are at Vdd.

In the next step, the T7 signal is first applied an one-shot pulse toenable the latch of INV5 and INV4 for Q[i] or QB[i] to reset IB[i] andI[i] of latch. Before Verify for one selected WL is performed, twoRecall signals RECALL1 and RECALL2 have to be performed to restore thestored 2-bit program data in two C_(SEG) capacitors or Dynamic Registersback to 2-bit Data-Buffers 340 through one Multiplier 602 and one SA604. In addition, one Program and Program-Inhibit MLC data patternsneeds to be restored back to one program buffer of 304. That is whythree clocks of RW_RES, RECALL1, and RECALL2 and three T7 clocks inbetween are required to enable SA 604. Once above 2-bit MLC data ofprogram data is ready, the Multiple-WL Program-Verify operation can beperformed by one-shot VFY thereafter.

The new Program and Program-Inhibit 2-bit data will be sent back to twoC_(SEG) capacitors again, which can be done by two one-shot L2A1 andL2A2. A new cycle of Program-Verify is then moved to next selected WL insame VFY1 of same WL voltage of previous WL. The above Program-Verifycycles would be performed on all selected multiple WLs. Then wholemultiple-WL simultaneous Program will be performed again with risingVpgm pulse. This iterative Program operation will end once all selectedmultiple WLs are completely programmed to meet the desired stored data.

FIG. 7D is a flow chart showing a method for the preferred Multiple-WLand All-GBL MLC simultaneous Program operation in accordance with themulti-bit static PB circuit shown in FIG. 5B. The method is applicablefor performing MLC Multiple-WL and All-GBL simultaneous Programoperation for both 2D and 3D HiNAND2 arrays according to an embodimentof the present invention. As shown, the method starts from a step 740 toload external 1-page or 1-WL data to the designated N-bit Data Registersequentially for all Multiple WLs. The data can be 1×N-bit SLC, 2×N-bitMLC, 3×N-bit TCL or 4×N-bit XLC.

When a first WL data is successfully loaded into N-bit Data Register,then it is immediately transferred to the corresponding N-bit CacheRegister as seen in step 742. When the first WL data is successfullyloaded into N-bit Cache Register, then it is immediately transferred tothe corresponding N-bit Program Buffer Register that is made of N localLBL capacitors in the designated areas of HiNAND2 array as shown in step744.

Then next step 746 is to check if all the desired program data ofMultiple WLs being successfully loaded in the designated metal1 LBLcapacitors? If not, then the loading from external I/O to LBL capacitorswill be repeated (step 748) for next page until it completes. If yes,then the step 750 is to start the Multiple-WL simultaneous Program. Theone-shot pulse of Vpgm for Multiple selected WLs one per Segment orGroup should be the same along with Vpass on multiple unselected WLs.

Once program time is due, then a Recall destructive operation of step752 is preferably being implemented prior to the Program-Verifyoperation in step 754. The reason needs to do the Recall is to restoreMultiple programmed WL data that are stored in the corresponding N-bitLBL metal1 capacitors as seen in FIG. 4A and FIG. 4B. For example, ifthe stored data is the MLC data, then it requires 3 N-bit CacheRegisters to store total three N-bit MLC data for each WL in three rowsof LBL metal1 capacitors. For 16-WL MLC data simultaneous Program, therestoring of 16-WL MLC data takes 3×16=48 clock cycles for 3-bit MLC WLdata.

Since the stored 3-bit MLC data are being restored back into 3-bit CacheRegister per GBL, then the data read from the selected WL bit can becompared against to the stored data. Thus the Program-Verify operationis activated at step 754. Note, the Program-Verify operation of HiNANDmemory cells is using DRAM-like charge-sharing scheme for HiNAND2 orHiNAND1 Read operations that need to precharge and discharge the metal1LBL and metal2 GBL lines (details are can be seen in earlier sections ofthe specification and skipped here for the description simplicity).Note, the restoring of the first multiple WLs' data of correspondingmetal1 LBL and metal2 GBL capacitors should be preferably done duringthe lengthy Multiple-WL Program operation to save the firstprogram-verify time because all N-bit GBL line buses are free in thatperiod.

In step 756 a successful Program-Verify operation is done for the firstN-bit data of the selected WL after the first iterative Programoperation. The successfully verified data in Data Register are flippedto V-inhibit and is transferred to dynamic cache in parallel. Then thenew set of Program and Program-Inhibit patterns are restored back to thecorresponding metal1 broken LBL capacitors (step 758) for next-bit ofMLC Program in the same WL.

A check operation is then executed (step 760) if all bits of each WL MLCdata being Program-Verified. If not, move to the next WL (page) in step762 to repeat the above Program-Verify steps 752-758 until allmultiple-WL MLC data completely pass Program-Verify (step 764), then themethod for performing MLC Multiple-WL and All-GBL simultaneous Programoperation for both 2D and 3D HiNAND2 arrays ends at step 766.

FIG. 8 is a diagram showing a preferred set of bias voltage conditionsof array control signals for Multiple-WL & All-GBL simultaneous Readoperation based on the HiNAND1 array shown in FIG. 2A according to aspecific embodiment of the present invention. A preferred set of biasvoltage conditions of several key array control signals are included ina table for performing a preferred J-WL & All-GBL simultaneous Readoperation divided into 8 steps. The bias conditions for multiple controlsignals in each step are listed in one column of the table. Theoperation is based on the HiNAND1 array shown in FIG. 2A with only Jbroken metal1 GBL lines and capacitors only without being furtherdivided into L Segment lines according to a specific embodiment of thepresent invention. The so-called J-WL and All-GBL simultaneous Readoperation means the number of the selected WLs can be flexibly variedfrom 1 to J with an identical address in the selected NAND String of theJ selected Blocks. The number of selected GBL lines is N-bit, thus it istermed as J-WL and All-GBL simultaneous Read. The simultaneous J-WL andAll-GBL Read operation is made possible because a novel Charge-sharingscheme is adopted for HiNAND1 array, regardless of SLC, MLC, TLC and XLCRead.

The key HiNAND1 array's selected and unselected control signals includeDIV_EN, CSL, PRE, GBLps, SEG, SSL, GSL, WL and GBL in accordance withFIG. 2A, regardless of SLC, MLC, TLC and XLC storages according to theembodiment of the present invention. As shown in FIG. 8, the J-WL andAll-GBL simultaneous Read operation is preferably being divided into 8steps from the step 1) of precharging all J N-bit metal1 broken GBLcapacitors in all Groups of the HiNAND1 array with a preferredV_(precharge)≧Vdd from J GBLps lines to the last step 8) to send out thewell-distinguished N-bit page digital data. Step 4) is to provide areduced GBL voltage Vdd/M(J) for Off-state cells by charge-sharing abroken GBL capacitor with all GBL capacitors. M(J) is a function of J(i.e., the charge-sharing effect varies for different Group withdifferent location relative to the page buffer circuit in the HiNANDarray). The N-bit page data are read from J selected WLs, loadedserially into one or two N-bit Data Registers (top or bottom), and thentransferred in parallel to one N-bit Cache Register in unit of one-WLsize. Lastly, each WL-data in the N-bit Cache Register are thentransferred to NAND's multiple I/Os in a pipeline manner. Today, theregular NAND or ONFI NAND I/O numbers are either 8 or 16.

Typically, one WL Read voltage is termed as V_(Rn), the 63 unselected WLpass voltage is denoted as Vread=6V for a 64-cell 2D NAND String. Thenumber of V_(Rn) values is one V_(R1) for SLC, 3 (V_(R1), V_(R2),V_(R3)) for MLC, 7 V_(Rn) for TLC, and 15 V_(Rn) for XLC.

FIG. 9 is a diagram showing a preferred set of bias voltage conditionsof array control signals for Multiple-WL & All-GBL simultaneous Readoperation based on the HiNAND2 array shown in FIG. 2B according to aspecific embodiment of the present invention. A preferred set of biasvoltage conditions of several key array control signals are included ina Table for performing a preferred J-WL & All-GBL simultaneous Readoperation executed in 8 steps. The bias conditions for multiple controlsignals in each step are listed in one column of the Table. Theoperation is based on the HiNAND2 array shown in FIG. 2B with J Groupsdivided by J−1 MGBL transistors connected by J broken Group GBL metal2lines according to an embodiment of the present invention. As shown inFIG. 2B, each Group is further divided into Segments and each Segment isfurther divided by n broken LBL metal1 lines. Each broken LBL metal1line comprises K Blocks. And each Block comprises N 64-cell Stringsextending in X-direction.

Since HiNAND2 array has 2-level BL-hierarchical structure, thus morearray control signals than HiNAND1 are required to take care of bothdivided metal2 broken J GBL and metal1 broken L LBL lines andcapacitors. The key HiNAND2 array includes two new control signals DI_1and PRE_1, and new LBL-divided NMOS MHV transistor MDBLp in addition toother HiNAND1 control signals like DIV_EN, CSL, PRE, GBLps, SEG, SSL,GSL, WL, and GBL in accordance with FIG. 2B, regardless of SLC, MLC, TLCand XLC storages of the present invention.

Similarly, the preferred J-WL and All-GBL simultaneous Read operation ispreferably divided into 8 steps from the step 1) of precharging all JN-bit metal2 broken GBL to the last step 8) to send out thewell-distinguished N-bit page digital data, read from J selected WLserially. Step 4) is also to provide a reduced GBL voltage Vdd/M(J) forOff-state cells by charge-sharing a LBL capacitor with corresponding GBLcapacitor for the selected Group. Again, M(J) is a function of J.

FIG. 10 is a diagram showing a first preferred set of bias voltageconditions of array control signals for Multiple-WL & All-GBLsimultaneous Program operation based on the HiNAND1 array shown in FIG.2A according to a specific embodiment of the present invention. Asshown, a set of bias voltage conditions of several key array controlsignals is provided for 7 steps of an option 1 J-WL & All-GBLsimultaneous Program operation for the HiNAND1 array shown in FIG. 2A ofthe present invention. The selected/unselected key control signalsassociated with the 2D HiNAND1 array include DIV_EN, CSL, PRE, GBLps,SEG, SSL, GSL, WL, and GBL (referring to FIG. 2A). These bias conditionsare applicable regardless of SLC, MLC, TLC and XLC storages of thepresent invention. For example, in step 2) of precharging GBL ofselected Group, GBLps associated with the selected Segment is coupled toVinh (e.g., V_(inhibit) voltage)>Vdd for charging the broken GBLcapacitor associated with a selected Segment, the charge is then trappedin the corresponding cell channels of the Strings in selected Block. AllGBL lines are subjected to, from the PB, the loaded page data pattern inVdd/Vss respectively for inhibit/program cells. In another example, atstep 6), a Recall operation is to restore multiple-WL N-bit program datafrom a Dynamic Cache made of broken LBL capacitors back to thecorresponding bits of one Static PB which is shared by multiple-WL SLCdata before a Program-Verify operation is performed. The selectedprogrammed WL is switched from Vpgm voltage to VFYn (n=1 for SLC, n=3for MLC, n=7 for TLC, and n=15 for XLC).

FIG. 11 is a diagram showing a second preferred set of bias voltageconditions of array control signals for Multiple-WL & All-GBLsimultaneous Program operation based on the HiNAND1 array shown in FIG.2A according to a specific embodiment of the present invention. Asshown, another preferred set of bias voltage conditions of severalcontrol signals is provided for 7 steps of an option 2 J-WL & All-GBLsimultaneous Program operation for the HiNAND1 array shown in FIG. 2A ofthe present invention. The key control signals include DI, DIV_EN, CSL,PRE, LBLps, SEG, SSL, GSL, WL, LBL, and GBL are associated with the 2DHiNAND1 array (FIG. 2A) regardless of SLC, MLC, TLC and XLC storages ofthe present invention. In the option 2 operation, all steps aresubstantially the same as option 1 operation except in precharging stepthe GBLps line is coupled to just the Vdd voltage rather than higherV_(inhibit) voltage to save power for precharging while usingconventional SB coupling effect for cell Program.

Unlike the above mentioned (FIG. 8 and FIG. 9) J-WL and All-GBLsimultaneous Read operation for both HiNAND1 and HiNAND2 arrays, themaximum number of multiple-WL simultaneous Program should not be limitedby J number, although it is optimized to be less than 20 in HiNAND Readas a same design guideline used in conventional DRAM charge-sharingsensing scheme. In this preferred simultaneous Multiple-WL Programoperation, no charge-sharing concern is involved.

FIG. 12 is a diagram showing a first preferred set of bias voltageconditions of array control signals for Multiple-WL & All-GBLsimultaneous Program operation based on the 2D HiNAND2 array shown inFIG. 2B, regardless of SLC, MLC, TLC and XLC storages, according toanother specific embodiment of the present invention. As shown, apreferred set of bias voltage conditions of several control signals isprovided for an option 1 Multiple-WL & All-GBL simultaneous Programoperation for the 2D HiNAND2 array shown in FIG. 2B of the presentinvention. The key control signals such as DI, DIV_EN, CSL, PRE, LBLps,SEG, SSL, GSL, WL, LBL, and GBL are included for executing a preferredMultiple-WL & All-GBL simultaneous Program operation in 7 steps for the2D HiNAND2 array, regardless of SLC, MLC, TLC and XLC storages of thepresent invention.

Like the above mentioned J-WL and All-GBL simultaneous Read and Programoperation for the HiNAND1 array, the maximum number of multiple-WLsimultaneous Program of the HiNAND2 array should not be limited by Jbecause no charge-sharing concern is involved.

FIG. 13 is a diagram showing a second preferred set of bias voltageconditions of array control signals for Multiple-WL & All-GBLSimultaneous Program operation based on the 2D HiNAND2 array shown inFIG. 2B, regardless of SLC, MLC, TLC and XLC storages, according to yetanother specific embodiment of the present invention. As shown, apreferred set of bias voltage conditions is provided for an option 2Multiple-WL & All-GBL simultaneous Program operation for 2D HiNAND2array shown in FIG. 2B of the present invention. The key control signalssuch as DI, DIV_EN, CSL, PRE, LBLps, SEG, SSL, GSL, WL, LBL, and GBL areincluded for executing a preferred Multiple-WL & All-GBL simultaneousProgram operation in 7 steps for the 2D HiNAND2 array, regardless ofSLC, MLC, TLC and XLC storages of the present invention.

Like the above mentioned Option 1 J-WL and All-GBL simultaneous Read andProgram operation for the HiNAND1 array, the maximum number ofmultiple-WL simultaneous Program of the HiNAND2 array should not belimited by J because no charge-sharing concern is involved.

FIG. 14 is a diagram showing a preferred set of bias voltage conditionsof 2D HiNAND array for a Multiple-WL & All-GBL simultaneous Eraseoperation using Channel-Erase scheme, regardless of SLC, MLC, TLC andXLC storages, according to an alternative embodiment of the presentinvention. As shown, a preferred set of bias voltage conditions isprovided for performing Multiple-WL & All-GBL simultaneous Eraseoperation using FN-channel tunneling Erase scheme as used forconventional 2D NAND flash based on 2D HiNAND1 array (Embodiment 1 inFIG. 2A) and 2D HiNAND2 array (Embodiment 2 in FIG. 2B) with dispersedBlocks. The biased conditions for the selected and unselected controlsignals including DI, DIV_EN, CSL, PRE, GBLps, SSL, GSL, WL, and GBL fora preferred Multiple-WL & All-GBL simultaneous Erase operation forHiNAND1 array shown in FIG. 2A, regardless of SLC, MLC, TLC and XLCstorages of the present invention, are summarized in a Table in FIG. 14.In the same Table, the biased conditions for control signals DI, DIV_EN,CSL, PRE, LBLps, SEG, SSL, GSL, WL, LBL, and GBL are also listed for apreferred Multiple-WL & All-GBL simultaneous Erase operation for HiNAND2array shown in FIG. 2B, regardless of SLC, MLC, TLC and XLC storages ofthe present invention.

In an embodiment, each Erase operation includes two setup steps such asErase Setup1 and Erase Setup2 and one execution step of Erase Start asshown in FIG. 14. As shown, in the first setup step, by using aWL-decoder circuit including one 20V NMOS pass-transistor (not shown)without need of any pull-down transistor, the unselect WLs, SSLs andGSLs control signals are being shut off in a floating state at 0V.Conversely, the selected WLs, SSL and GSL signals are precharged withVdd-Vt. The rest of other varied gate signals of DI, DIV_EN, PRE and SECare preferably biased with Vdd and two power lines of CSL an LBLps arealso biased at Vdd to help prevent two String-select transistors MS andMG in each String from being punch-throughed when V_(inhibit) voltage˜7Vis precharged into LBL or GBL capacitors associated with the selectedBlock of a selected Segment of a selected Group.

The second setup step is used to prepare for the subsequent HV 20V Erasestep. All initial HiNAND array low-voltage bias conditions applied toDI, DIV_EN, PRE, LBLps, SEC, SSL, GSL, WL(unselected ones), LBL and GBLare preferably turned into floating states with their respectiveprecharged voltages initially obtained in the Setup1 step bydisconnecting the corresponding ports from their respective drivercircuits excepting that the selected WL voltage is coupled to 0V.

The Erase Start step is to execute the desired Block-based Eraseoperation. Unlike prior art, the erase size of the present invention canbe reduced down to single, randomly selected WL by setting WL=0V withrespect to TPW voltage being switched from 0V as set in the Setup2 stepto a high Vers voltage of 20V.

Since 2D NAND uses the FN-tunneling scheme, thus the electrons would beelectrically expelled out from each cell's floating-gate to cell'schannel. As a result, for each selected WL page each cell's Vt will bereduced below −2.0V after Erase-Verify over each iterative erase pulse.For M WLs to be erased in each String within each Block, M WLs in oneString are respectively coupled to 0V. Similarly, one or more WLs can beselected for Erase in one or more Groups with WLs being coupled to 0Vwith the selected TPW voltage being ramped to 20V.

FIG. 15 is a diagram showing a set of bias voltage conditions preferredfor 3D HiNAND array for Multiple-WL & All-GBL simultaneous Eraseoperation using gate-induced drain leakage (GIDL) Erase scheme,regardless of SLC, MLC, TLC and XLC storages, according to anotherspecific embodiment of the present invention. As shown, a preferred setof bias voltage conditions is provided for performing Multiple-WL &All-GBL simultaneous Erase operation using GIDL Erase scheme for a 3DHiNAND array with either 1-level BL (Embodiment 1) and 2-level BL(Embodiment 2) architecture with dispersed Blocks. For example, thebiased conditions for the selected and unselected control signalsinclude DI, DIV_EN, CSL, PRE, LBLps, SEG, SSL, GSL, WL, LBL and GBL fora preferred Multiple-WL & All-GBL simultaneous Erase operation forEmbodiment 2, regardless of SLC, MLC, TLC and XLC storages of thepresent invention, are briefly explained below.

The Erase operation for 3D HiNAND array is preferably performed the sameas 2D HiNAND array with erase-size flexibly reducing down to single WLexcept with one major difference in the Erase scheme. Unlike a FN-Erasescheme used for 2D HiNAND array (see FIG. 14), a scheme withGIDL-induced hot-hole to erase the electrons stored in thecharge-trapped layer is used for 3D HiNAND array due to the built-indeep-layer cell structures. Therefore, the selected bit line and sourceline of the selected 3D String have to be coupled to Vers, rather thanin floating state as used for 2D String. Similarly, the voltages of DI,DIV_EN, PRE, LBL, LBLps, SEC have to coupled to Vers to allow the fullVers voltage pass to the selected bit line and source line without adrop to ensure the success of Erase operation.

Unlike 2D HiNAND2 array having a 64-cell String is very popular, 3DHiNAND array has less number of cells in one String. Thus, 3D HiNAND2simultaneous operation has to be re-adjusted accordingly. In this case,a similarly mixed WL number of three simultaneous operations arepreferably performed in 3D HiNAND2 array with a shorter String length issummarized in Table 7 below.

TABLE 7 Preferred operation Simultaneous Simultaneous Simultaneous EraseProgram Read WL number 64/32 16 or 8 16 or 8

FIG. 16 is a simplified circuit diagram showing a 3D HiNAND2 array with2-transistor GBL/LBL-divided device and U-shaped vertical-channel Stringaccording to an embodiment of the present invention. As shown, 3DHiNAND2 array includes J−1 paired 2-transistor GBL/LBL-divided device tofrom broken metal2-GBL/metal1-LBL lines (or capacitors) to form multipleGroups (e.g., Group 1 through Group J) of multiple Segments of multiplememory Blocks MU made by U-shaped vertical-channel Strings. Similar to2D HiNAND2 array, metal1 lines are one topological level lower thanmetal2 lines in device layout. Each top-level metal2 GBL line is brokeninto J metal2 GBL lines or capacitors, such as GBL_1 to GBL_J, by using(J−1) paired GBL-divided NMOS transistors, MGBLp. Gates of the (J−1)GBL-divided devices MGBLp are tied to J−1 respective signals ofDIV_EN[1] to DIV_EN[J−1] for forming the preferred broken metal2 GBL 3DHiNAND2 array. In an embodiment, the broken GBL_1 line capacitor inGroup 1 is directly connected to a first SA located at left end of thearray and the broken GBL_J line capacitor in Group J is connected to asecond SA located at the right end of the array, similar to a 2D HiNAND2array with 2-sided SA of the present invention shown in earlier sectionsof the specification.

Similarly, each bottom-level metal1 LBL line is broken into n metal1 LBLlines or capacitors, such as LBL_1_1_1 to LBL_1_1_n, by using (n−1)paired LBL-divided NMOS transistors, MDBLp. The device type of MDBLp issimilar to that of a 3D NAND String-select transistor, MG or MS.Totally, the n−1 paired transistors MDBLp have their gates tied torespective n−1 signals, DI_1_1[1] to DI_1_n−1[1], for forming thepreferred broken metal1 LBL 3D HiNAND2 array. The 3D source nodes of thepaired MGBLp transistors are shorted by a metal and the source nodes ofanother paired MDBLp transistors are shorted by another metal.

Besides, n different ends of n broken LBL capacitors are connected to ncorresponding power lines, such as LBLps_1_1[1] to LBLps_1_n[1]. Each 3DHiNAND2 memory Block has N cells connected in series forming a U-shapedvertical-channel String with one back-gate NMOS transistor, MC, havingits gate tied to BG_1[1]. The U-shaped vertical-channel Strings arebased on traditional multilayered BiCS (Bit-Cost Scalable) or P-BiCSU-shape cell-string manufacturing processes. Detail descriptions on theprocesses of forming the U-shaped vertical-channel Strings and theiroperations can be found in U.S. Pat. No. 8,169,826, incorporated fullyas references. By dividing the GBL line to multiple Groups as shownabove, the preferred Multiple-WL and All-GBL simultaneous Read andProgram operations like the 2D HiNAND2 array can be also executed in the3D HiNAND array without much changes in memory cell manufactureprocesses.

According to some traditional 3D NAND technologies, for example, in U.S.Pat. No. 8,169,826, both BiCS and P-BiCS use a multi-stacked memoryarray with a few constant critical lithography steps regardless ofnumber of stacked layers to keep a continuous reduction of bit cost.Therefore, whole stack of electrode plate is punched through and pluggedby another electrode material. More information about P-BiCS or BiCSstructure can be referred to U.S. Pat. No. 8,334,551, U.S. Pat. No.8,169,826, U.S. Pat. No. 8,189,391, U.S. Pat. No. 8,194,453, U.S. Pat.No. 8,203,882, U.S. Pat. No. 8,334,551, and U.S. Pat. No. 8,335,111,incorporated fully as references. All of the disclosed vertical 3D NANDarray circuits are 2-level non-broken-BL structures for performingsingle-WL and All-GBL Read, Program and Program-Verify operations with ahigh power consumption due to the heavy capacitance loading on each longunbroken metal2 GBL line along with corresponding unbroken metal1 LBLline. While with the improved 3D HiNAND array with broken metal2 GBL andbroken metal1 LBL lines according to the embodiments of the presentinvention, multiple-WL and All-GBL Read and Program operations can beperformed due to dramatically reduction of the current for executingRead and Program operations.

In the traditional 3D NAND architecture, only one end of each selected,long but unbroken, top-level, metal2 GBL is connected to eachcorresponding SA at right end of the array through a NMOS transistor.Each GBL line crosses a plurality of horizontal 3D-NAND memory Blocks.And each 3D-NAND memory Block includes a plurality of 3D NAND MUs. Each3D MU further includes one vertical 3D NAND String with many 3D memorycells connected in series having a back-gate NMOS transistor, BTrb, inthe middle (or bottom) of the 3D NAND String having two NMOSString-select transistors, SSTrb and SDTrb, placed on top. The top drainnodes of all MUs within the same memory Block are connected together bya common but unbroken metal1 LBL line or capacitor.

Based on the 3D HiNAND's 2-level unbroken-BL structure, a high-currentprecharge operation to both GBL and LBL has to be performed initiallyprior to any 3D NAND Read operation but only happens on each GBL withoutLBL. Similar to the 2D NAND Read operation, each GBL line or capacitorhas two precharged voltages, such as Vdd-Vt of about 1.0V for thecorresponding stored bit data “1” and 0V for the corresponding storedbit data “0”, supplied by a N-bit PB that contains N SAs. Therefore,regardless of the nearest memory Block (MB) or the farthest MB from theone-end SA scheme's viewpoint, each traditional unbroken heavy and longGBL and each unbroken LBL capacitors have to be fully charged up toVdd-Vt or discharged to Vss by one corresponding bit of N-bit PB thatcontains one-bit of SA through each corresponding global HV transistorand each paired transistors of SSTra and SDTra with a common orseparated gate control signals of SGSa and SGDa within eachcorresponding LBL capacitor (see U.S. Pat. No. 8,169,826). In otherwords, high power consumption for both precharge and dischargeoperations of each metal2 GBL capacitors and its associated each metal1LBL capacitors has no discrimination on all selected MUs in eachselected MB of each selected common metal1 LBL line and all selected MBsin each selected common metal2 GBL line when the traditional 3D NANDwith 2-level BL-hierarchical structure is adopted for single-WL Programand Read scheme.

Unlike the above conventional 3D NAND Read and Program schemes, oneembodiment of a 3D HiNAND2 scheme of the present invention providedabove in FIG. 16 proposes a novel 3D architecture with modifications incircuit particularly in GBL and LBL layout to allow much powerfulMultiple-WL and All-BL simultaneous Read, Program and Program-Verifyoperations as explained below. Several alternative embodiments of the 3DHiNAND2 scheme with references to FIG. 17, FIG. 18 and FIG. 19 of thisapplication are further illustrated.

In an embodiment, as shown in FIG. 16, each long metal2 GBL has beenchanged to a plurality of broken or segmented metal2 GBLs, such asGBL_1, GBL_2, through GBL_J in one of the 3D HiNAND with a one-end SAscheme. The capacitance of each piece-wise, broken GBL_J line is only1/J of capacitance of traditional long GBL line. For example, if theright-most broken GBL_J is the one that is connected to the SA at theright end, then the GBL capacitor, C_(GBL) _(_) _(J), is a nearest oneconnected to the corresponding SA at right end. By contrast, theleft-most C_(GBL) _(_) ₁ capacitor would become the farthest oneconnected to the SA at the right end.

The newly inserted devices in between two adjacent broken C_(GBL) _(_)_(J) and C_(GBL) _(_) _(J-1) capacitors is a paired transistors of NMOSHV MLBLp with two gates tied to a common signal of DIV_EN line such asDIV_EN[1] to enable and disable the selection of the correspondingbroken GBL_1, and DIV_EN[2] to enable and disable the selection of GBL_2and lastly DIV_[J−1] to enable and disable the selection of thecorresponding broken GBL_J−1. The last one of the broken GBL_J isdirectly connected to its corresponding SA without going through anyMLBLp transistor.

In this 3D HiNAND2 operation, both DIV_[1]=DIV_[2]= . . .=DIV_[J−1]=Vread to allow the selection of GBL_1. The Vread ispreferably set to be about 6V to reduce the on-resistance of each MGBLptransistor to reduce the RC delays of precharge and dischargeoperations. Note, the GBL_1 precharge and discharge times are theslowest with the highest power-consumption for this 3D HiNAND2 Readscheme due to the largest RC from each one-end SA sensing viewpoint.Several scenario are shown below:

-   -   A) For reading GBL_1, the largest        RC=[(J−1)×R(MLBLp)]×[J×C_(GBL)],    -   B) For reading GBL_2, the RC=[(J−2)×R(MLBLp)]×[(J−1)×C_(GBL)],    -   C) For reading GBL_J−1, the RC=1×R(MLBLp)]×[2×C_(GBL)],    -   D) For reading GBL_J, the RC=1×C_(GBL) with zero R(MLBLp). The        smallest RC from right-end N-bit SA viewpoint.

More details of comparison between traditional 3D NAND with unbroken GBLand the 3D HiNAND2 of the present invention (see FIG. 16) with brokenGBL for 1-WL Read charge-sharing operation are summarized in thefollowing Table 8.

TABLE 8 1-WL and All-GBL Read charge-sharing operation Read comparison3D NAND 3D HiNAND2 Comment Each broken GBL with unbroken J broken J = 16each unbroken LBL line GBL GBL C_(GBL) loading to 16 C_(GBL)s  1 C_(GBL) 1/16 power precharge Jth memory Block near SA C_(GBL) loading to 16C_(GBL)s  2 C_(GBL)s  1/8 power precharge 15th memory Block C_(GBL)loading to 16 C_(GBL)s 15 C_(GBL)s 15/16 power precharge 2nd memoryBlock C_(GBL) loading to 16 C_(GBL)s 16 C_(GBL)s 16/16 = 1, i.e.,precharge 1st same power memory Block

The above explanation of the 3D HiNAND2 array is to show how to read oneWL by one WL from different broken GBL and impact of charge-sharing ifthe similar DRAM-like Latch-type SA is used for this 3D HiNAND2 Readoperation for one WL.

More comparison between traditional 3D NAND with unbroken GBL and the 3DHiNAND2 of the present invention (see FIG. 16) with broken GBL forMultiple J WLs All-GBL simultaneous Read charge-sharing operation isillustrated below in Table 9.

TABLE 9 J-WL and All-GBL Read charge-sharing operation Read comparisonfor 3D NAND 3D HiKAND2 Each broken unbroken GBL J broken GBL GBL witheach (J = 16) unbroken LBL line Precharge time of 16X One memory 1XSimultaneously all GBL lines and Block by one memory on 16 memory BlocksLBLs in 16 memory Block, thus one time only Blocks 16 times for 1 GBLV_(R) on selected WLs 16 V_(R)s for 16 WLs 1 V_(R) for 16 WLs # of LBL &GBL 16 times 1WL-by-1WL one time for 16-WL discharged for 16 WLs

In above 3D HiNAND2 flash array with broken-GBL but with non-broken LBLscheme, it allows the Multiple-WL simultaneous Read, Program, andProgram-Verify operations to be performed within multiple memory Blocks.However, for traditional 3D NAND flash array, the Multiple-WLsimultaneous Read, Program, and Program-Verify operations cannot beperformed even within only one memory Block.

For the 3D HiNAND2 flash array, it includes J broken metal2 GBL linesand K broken metal1 LBL lines. The values of J and K can be different orsame. There are two major advantages to change one unbroken LBL into Kbroken LBL lines per one broken GBL line is for the preferred low-power,simultaneous, fast, multiple-WL Program and Program-Verify operations.In an embodiment, the scheme of one of K broken LBL lines consumes only1/K of V_(inhibit) precharge current of the whole unbroken LBL line. Asexplained in 2D HiNAND2 array with a broken LBL structure, each of the Kbroken LBLs would have only 1/K capacitance of whole unbroken LBLcapacitor. In a preferred Non-SBPI method of the present invention, only1/K power is required to precharge each selected broken LBL capacitor toV_(inhibit) voltage, which is about 7V. In another embodiment, thescheme of the K broken LBL lines allows K-WL and All GBL simultaneousRead, Program, and Program-Verify operations to be performed in only onesmall MB, rather than multiple big MBs. Thus, this scheme provides morefine multiple-WL & All-GBL Program.

There is a disadvantage with the K broken LBL structure for Kth brokenLBL would be associated with only 1/K capacitance of whole unbroken LBLcapacitor. Due to the required charge-sharing scheme for the preferredMultiple-WL Read and Program-Verify operation, the 3D HiNAND2 array withbroken-LBL structure still has its application for multiple-WL Readexcept the MB of GBL_J. The results for one-end SA 3D HiNAND2 scheme aresummarized in Table 10 below.

TABLE 10 16-WL and All-GBL Read charge-sharing operation Comparison 3DHiNAND2 3D HiNAND2 For one-end SA Broken GBL but non- Broken GBL &broken LBL scheme broken LBL scheme 16-WL simultaneous Yes but consumesYes but consumes program in 16 16X V_(inhibit) power 1X V_(inhibit)power memory Blocks? 16-WL simultaneous No Yes program in one memoryBlock? Multiple-WL & All- Yes Yes GBL Read in 16 memory Blocks?Multiple-WL & All- No Yes on GBL_16 only GBL Read in one memory Block?

In an alternative embodiment, a 3D HiNAND2 scheme with two-ended N-bitSA on each GBL including a first N-bit SA placed at the right end and asecond N-bit SA placed at left end. For example, in a 3D HiNADN2 with 16broken GBL scheme and two-ended SA, there are two nearest and twofarthest GBL capacitors per one metal2 GBL. In particular, two nearestGBL capacitors are GBL_1 from the far-left SA viewpoint and GBL_16 fromthe far-right SA viewpoint, and two farthest GBL capacitors are GBL_8from the far-left SA viewpoint and GBL_9 from the far-right SAviewpoint, here J=16. The detailed operations of this two-ended SAassociated with the 3D HiNAND2 array with broken GBL and broken LBL orunbroken LBL schemes would be similar to the one-ended SA associatedwith the same 3D HiNAND2 array explained previously and thecorresponding descriptions are then skipped here for simplicity.

FIG. 17 is a simplified circuit diagram showing a 3D HiNAND2 array with3-transistor divided-GBL/LBL device and U-shaped vertical Stringaccording to another embodiment of the present invention. It is a secondembodiment of 3D HiNAND2 circuit with divided GBL devices for the brokenGBLs and broken LBLs. The divided GBL devices include one paired NMOStransistors of MGBLp with a common gate connected to DIV_EN and oneBack-gate NMOS transistor of MC with its gate tied to BG. Similarly, thedivided LBL devices are comprised of one paired transistors of MLBLpwith a common gate tied to DI_1 and one back-gate NMOS transistor, MC,with gate tied to BG_[1].

Besides the one divided device is added in between two adjacent brokenGBL capacitors and two adjacent broken LBL capacitors, there areadditional devices are added at one end of each LBL and each GBL. Thesedevices are like the above said devices for the Divided or broken LBLand GBL.

For example, these devices include one-paired MLBLps with the commongate tied to PRE_1_1[1] to PRE_1_n[1] with power line of LBLps_1-1[1] toLBLps_1-n[1]. Similarly, the same MGBLps transistor can be added to eachbroken GBL line for precharging or discharging the V_(inhibit) or Vss.But in order to save one the transistors and power line, GBLps, is notadded into each broken GBL.

The differences between the embodiment in FIG. 16 and the embodiment inFIG. 17 is to add one extra back-gate transistor MC in series with thepaired 2-transistor GBL-divided device MGBLp to form a 3-transistorGBL-divided device, and similarly, add one back-gate transistor MC inseries with the paired 2-transistor LBL-divided device MDBLp. Each addedtransistor MC has its gate respectively tied to a signal BG. All othercircuits such as two-sided SA and 3D NAND Strings are kept the same as atraditional U-shaped vertical NAND flash technology.

FIG. 18 is a simplified circuit diagram showing a 3D HiNAND2 array with1-transistor divided-GBL/LBL device and with U-shaped vertical-channelString according to yet another embodiment of the present invention. Itis a third embodiment of 3D HiNAND2 flash array circuit. As shown, itincludes both broken metal2 GBL lines and broken metal1 LBL lines. Thedivided devices do not include one paired transistors but one back-gatetransistor (such as MGBLp, or MDBLp). For example, between two adjacentbroken divided metal2 GBL lines of GBL_J−1 and GBL_J, a GBL-dividedtransistor is a 1-poly NMOS transistor MGBLp with its gate tied toDIV_EN[J−1]. A LBL-divided 1-poly NMOS transistor MDBLp with its gatetied to DI_1_1[N] is to connect two adjacent broken metal1 LBL lines,LBL_1_1_1 and LBL_1_1_2. To precharge or discharge each LBL line orcapacitor, it goes through each corresponding LBLps line through a 3DNMOS transistor of MLBLs. All other circuits such as two-sided SA and 3DNAND Strings are kept the same as the traditional U-shaped vertical NANDflash technology.

FIG. 19 is a simplified circuit diagram showing a 3D HiNAND2 array with1-transistor divided-GBL/LBL device and with straight vertical-channelString according to still another embodiment of the present invention.As shown, the 3D HiNAND2 array with broken GBL and broken LBL scheme hasa different MU String structure. The two String-select transistors withone on top and one on bottom. But the way of dividing GBL and LBL aresimilar to previous embodiments shown in FIG. 17 and FIG. 18.

In this embodiment, both GBL and LBL divided devices are made of 1-polyNMOS transistors such as MGBLp and MDBLp. The 1-poly MGBLp transistorhas its gate tied to signal DIV_EN for forming a broken metal2 GBLstructure and the 1-poly MDBLp transistor has its gate tied to DI_1 forforming a broken metal1 LBL structure.

As shown, the second String-source select transistor is not at the topof String, Instead, it is formed at the bottom of the String with itsgate tied to signal GSL[1] and its source tied to signal CSL[1]. In thiscase, the number of memory cells MC in this 3D HiNAND String is halvedas compared to the String sizes shown in FIGS. 16-18.

FIG. 20 is a simplified circuit diagram showing a 3D HiNAND2 arraycompatible with vertical-gate NAND cell string scheme according to analternative specific embodiment of the present invention. As shown, the3D HiNAND2 array circuit includes a similar 2-level segmented or brokenGBL and LBL structure based on a vertical-gate 3D NAND flash technology.Examples of traditional vertical-gate lateral-channel 3D NANDarchitecture can be referred to U.S. Pat. No. 8,148,763, U.S. Pat. No.8,437,192, and U.S. Patent Application Publication No. 2012/0051137 A1,incorporated all for references.

Similarly, the broken LBL uses the same 8-transistor divided LBL devicewith their 8 gates tied to each common DI_1_1 signal line. As shown inFIG. 20, each long GBL has been divided into a plurality of broken GBLs(such as GBL_1 to GBL_J for total J broken GBL lines) or capacitors byinserting eight 1-poly NMOS transistors, MGBLp, in a vertical column inparallel with drain and source connected to two adjacent GBL lines orcapacitors and with 8 gates commonly tied to a signal DIV_EN_[J−1]. Thisis implemented similar to but slightly different from the previousembodiment shown in FIG. 19. In this embodiment, the vertical-gate 3Dstructure is adopted, thus multiple-layer of transistors are easier tostack on top of one another for eight stories than the previousembodiment with vertical-channel 3D structure. In a specific embodiment,the 3D HiNAND array with vertical-gate can be implemented by usingtraditional platform without process changes. Simply, the GBL divideddevices of MGBLp associated with the novel 3D HiNAND array are also madeof compatible vertical-gate structure on the same silicon die.

Since eight MGBLp transistors are formed in parallel between twoadjacent GBL_J lines or capacitors, thus the effective resistance oftotal eight MGBLp becomes ⅛ of one MGBLp. As a result, the RC delay foreach divided GBL becomes smaller 1/J as compared to one long unbrokenGBL line when gate signal voltage of DIV_EN_J=Vread=6V or higher. As aresult, the total RC delay of connecting all J GBL capacitors and J−1resistors of MGBLp is almost same without degradation of using thisbroken GBL scheme as one long GBL capacitance without MGBLp resistanceused in a prior-art 3D NAND. But if the accessed MBs are near SA inphysical layout, then the RC delay is much less than prior-art 3D NAND.As a result, a superior 3D HiNAND performance can be achieved based on aconventional vertical-gate 3D NAND design when the preferred broken 3DGBL structure is adopted therein.

Similarly, a broken LBL scheme can be also used for this 3D HiNAND Flasharray with a vertical-gate platform. In particular the broken LBL linecan be achieved by using 8-Transistor LBL-divided devices MDBLpconnected in parallel with their 8 gates tied to respective commonsignal DI_1_1[L−1].

Besides, one end of each broken LBL is connected to one correspondingpower line of LBLps_1_n though eight MLBLs with eight gates tied to onecommon signal of PRE_1_n. Similarly, one end of each broken GBL can alsobe connected to a corresponding power line of a GBLps bus.Alternatively, because each broken GBL capacitor voltage can beprecharged or discharged through the corresponding LBLps_1_n, in this 3DHiNAND2 structure with vertical-gate platform. This GBLps line can besaved to reduce the silicon area.

In addition, each preferred broken GBL is connected to two SA placed infar-left and far-right ends. As explained in 2D NAND Flash withtwo-ended SA per one broken GBL, the fastest and lowestpower-consumption GBLs are two, rather than one. Thus more flexibilityof the 3D HiNAND2 array can be planned for faster and superiorreliability NAND operation.

All the basic 3D HiNAND cell Program, Erase, and Read conditions in thisvertical-gate technology are fully compatible with traditional 3D NANDoperating conditions. The major attributions of this vertical-gate 3DHiNAND array are to use short and light broken-GBL and broken-LBLschemes to replace long and heavy un-broken GBL and LBL so that fastsimultaneous Multiple-WL and All-BL Program, Read, and Program-Verifyoperations can be achieved.

FIG. 21 is a diagram showing six decoding logics for eight layers of thevertical String-selected transistors of the 3D vertical-gate HiNAND2array structure of FIG. 20 according to a specific embodiment of thepresent invention. As shown, the GBL decoding scheme is executed throughsix GBL-select NMOS transistor connected in series with their six commongates tied to six control logics such as SS1B, SS1, SS2B, SS2, SS3B,SS3, and SS4B, SS4. These gate logic assignments are designed for8-layer vertical-gate 3D NAND Strings GBL selections. The detaildescription of these gate logic assignments is kept the same astraditional ones for the vertical-gate 3D NAND architecture which can befound in U.S. Pat. No. 8,437,192, incorporated fully as references.Thus, the 3D HiNAND2 broken-GBL and broken LBL preferred schemesaccording to an embodiment of the present invention can still beimplemented without change in the GBL-select scheme based on thetraditional 3D NAND technology. Regardless of any new design approachesof GBL-select circuit, the 3D HiNAND2 scheme of the present inventioncan still be applied.

Throughout the specification, all the 3D HiNAND2 arrays proposed above(FIGS. 16-20) have 2-sided SA and multiple-level broken-BL hierarchicalstructures. However, all of them can be turned into 3D HINAND2 arrayswith 1-sided SA and multiple-level hierarchical BL structures so that afaster and less-power consumption of the preferred Charge-sharing,Precharge and Discharge Read and Verify operations can be performed.

The detailed operations of the vertical-gate 3D NAND flash using theHiNAND2 BL-hierarchical structure of the present invention forMultiple-WL and All-BL Read, Program and Program-Verify operations wouldbe same as the previous descriptions for the 2D HiNAND2 flash array andthe 3D HINAND2 array with U-shaped vertical-channel String.

Although the above has been illustrated according to specificembodiments, there can be other modifications, alternatives, andvariations. It is understood that the examples and embodiments describedherein are for illustrative purposes only and that various modificationsor changes in light thereof will be suggested to persons skilled in theart and are to be included within the spirit and purview of thisapplication and scope of the appended claims.

What is claimed is:
 1. A high-density NAND (HiNAND) flash memory arraywith 1-level broken-bit-line hierarchical architecture for performingmultiple-WL All-BL simultaneous Program, Program-Verify, and Readoperations, the HiNAND flash memory array comprising: a NAND memoryarray arranged in a first plurality of Groups per N columns respectivelyassociated with N global bit lines (GBLs) parallel to each othercascaded in a row, the N GBLs being respectively divided into the firstplurality of broken-GBLs separated/connected from/to each othercorrespondingly by a row of N Group-divided devices, each Group beingfurther divided into a second plurality of Segments such that the Nbroken-GBLs associated with the Group are respectively divided into thesecond plurality of N segmented-GBLs separated/connected from/to eachother correspondingly by a row of N Segment-divided devices, eachSegment including multiple Blocks, each Block including M Pages of NANDmemory cells forming into N Strings, each String having M NAND memorycells connected in series capped by a first String-select device coupledto the corresponding segmented-GBL and a second String-select devicecoupled to a common source line in parallel to a word line (WL) of eachPage; a row of N precharge pull-down devices per Segment with Nindividual drains and sources respectively coupled between the Nsegmented-GBLs associated to the Segment and a precharge-power line inparallel to the common source line connected to a voltage decoder forprecharging and discharging all the N segmented-GBLs in the Segmentselected from any Group independent from other Segments in all Groups; apage buffer having N-bit ports to couple with the N GBLs, the pagebuffer comprising at least a first Data Register coupled with a firstCache Register located at a first end of the first plurality of columnsnear a first one of the first plurality of Groups of the array; whereineach row of N Group-divided devices is commonly gated by one of firstcontrol signals, each row of N Segment-divided devices is commonly gatedby one of second control signals, each row of N precharge pull-downdevices per Segment is commonly gated by one of third control signals,multiple Pages across the NAND memory array can be selected onone-page-per-block basis from multiple dispersed Blocks in multipledifferent Segments of one or more Groups for at least partiallyperforming simultaneous Program, Program-Verify, and Read operations. 2.The HiNAND flash memory array of claim 1 wherein each Group-divideddevice, each Segment-divided device, each precharge pull-down device,each first String-select device, and each second String-select deviceare substantially a same type transistor as an 1-poly NMOS low-voltage(LV) transistor operating under a low-voltage Vdd precharge scheme. 3.The HiNAND flash memory array of claim 1 wherein each Group-divideddevice, each Segment-divided device, each precharge pull-down device,each first String-select device, and each second String-select deviceare substantially a same type transistor as an 1-poly NMOSmedium-high-voltage (MHV) transistor operating under a MHV V_(inhibit)˜7V precharge scheme.
 4. The HiNAND flash memory array of claim 1wherein M is selected from 8, 32, 64, or other integer numbers dependingon NAND design density and N is 65,536 for 8 KB Page size andupgradeable for a larger Page size.
 5. The HiNAND flash memory array ofclaim 1 wherein each NAND memory cell is configured to store 2-stateSLC, or 4-state MLC, or 8-state TLC, or 16-state XLC, or even 256-stateanalog values.
 6. The HiNAND flash memory array of claim 1 wherein eachbroken-GBL comprises a metal line having a parasitic capacitor served asa unit for storing precharged voltages during all-GBL Read operationusing a charge-sharing scheme or storing GBL program and program-inhibitvoltages during All-GBL program operation.
 7. The HiNAND flash memoryarray of claim 3 wherein each precharge-power line is a metal line laidin parallel to the common source line at a same level below the GBL andis configured for precharging each corresponding segmented-GBL to avoltage level of low-voltage Vdd up to a MHV V_(inhibit) of ˜7V ordischarging to a designated voltage level below the precharged voltagelevel.
 8. The HiNAND flash memory array of claim 1 wherein multipleprecharge-power lines respectively associated with multiple Segmentsfrom one or more Groups are configured to perform a simultaneousprecharge operation independently by setting corresponding first controlsignals, corresponding second control signals, and corresponding thirdcontrol signals to predetermined voltages for performing simultaneousmultiple-WL and all-BL Read operation on the basis of one Page per oneSegment per one Group.
 9. The HiNAND flash memory array of claim 1wherein each segmented-GBL comprises a metal line parasitic capacitorunit configured to be a dynamic cache register for storing temporaryprogram page data during simultaneous multiple-WL and all-BL Programoperation.
 10. The HiNAND flash memory array of claim 9 wherein multiplesegmented-GBL metal line parasitic capacitor units associated withdispersed Blocks in different Segments of one or more Groups areconfigured to independently latch and trap a LV system-operation voltageVdd for program-inhibit and a Vss voltage or a voltage less than Vdd-Vtfor program by directly coupling via the N GBLs from the page bufferwith one WL page data pattern of Vdd for program-inhibit and Vss or avoltage less than Vdd-Vt for program, wherein Vt is a threshold voltageof the precharge pull-down device, for executing a simultaneous All-GBLProgram operation based on a self-boosting-program-inhibit scheme. 11.The HiNAND flash memory array of claim 10 wherein multiple segmented-GBLmetal line parasitic capacitor units associated with dispersed Blocks indifferent Segments of one or more Groups are configured to independentlylatch and trap a V_(inhibit) voltage above Vdd up to about 7V forprogram-inhibit and Vss voltage or a voltage less than Vdd-Vt forprogram by precharging each of N Segmented-GBLs to the V_(inhibit)voltage from the precharge-power line for each selected Segment, andcoupling via the N GBLs from the page buffer with a WL page data patternof Vdd for program-inhibit and Vss or a voltage less than Vdd-Vt forprogram, for executing a simultaneous All-GBL Program operation onmultiple selected Pages respectively in the multiple dispersed Blocksbased on the corresponding one WL page data pattern using anon-self-boosting-program-inhibit scheme.
 12. The HiNAND flash memoryarray of claim 1 comprising a 3D flash array structure with each Stringof memory cells being stacked in a third direction in a straightvertical-channel configuration, or U-shaped vertical-channelconfiguration, or vertical-gate lateral-channel configuration, the thirddirection being perpendicular to both the first direction and the seconddirection, wherein each Group-divided device, each Segment-divideddevice, each pull-down device, each first String-select device, and eachsecond String-select device associated with a vertical-channel 3D NANDString configuration is selected from a one-transistor device of a sametype NMOS 1-poly transistor, a two-transistor device having two NMOS1-poly transistors with a common gate, and a three-transistor devicehaving two NMOS 1-poly transistors with a common gate plus a third NMOS2-poly transistor.
 13. A high-density NAND (HiNAND) flash memory arraywith 2-level broken-bit-line hierarchical architecture for performingmultiple-WL All-BL simultaneous Program, Program-Verify, and Readoperations, the HiNAND flash memory array comprising: a NAND memoryarray arranged in a first plurality of Groups per N columns respectivelyassociated with N global bit lines (GBLs) laid in parallel at a firstlevel through all Groups and N local bit lines (LBLs) laid at a secondlevel below the first level parallel to the GBLs through only a Segmentof each Group, the N GBLs being respectively divided into the firstplurality of N broken-GBLs separated/connected from/to each othercorrespondingly by a row of N Group-divided devices, each Groupcomprising a second plurality of Segments with each Segment beingdivided into a third plurality of Sub-segments such that the N LBLs perSegment are respectively divided into the third plurality of Nbroken-LBLs separated/connected from/to each other correspondingly by arow of N Segment-divided devices, each Sub-segment including multipleBlocks, each Block including M Pages of NAND memory cells forming into NStrings, each String having M NAND memory cells connected in seriescapped by a first String-select device coupled to a broken-LBLassociated with the Sub-segment and a second String-select devicecoupled to a common source line in parallel to a word line (WL) of eachPage; a row of N Segment-select devices respectively coupled the Nbroken-GBLs per Group at the first level to the N LBLs per Segment inthe Group at the second level; a row of N precharge pull-down devicesrespectively coupled the N broken-LBLs per Sub-segment to aprecharge-power line laid at a third level below the second level forprecharging and discharging all the N broken-LBLs in the Sub-segmentselected from any Segment of any Group independent from other Segmentsin all Groups; and a page buffer having N-bit ports to couple with the NGBLs, the page buffer comprising at least a first Data Register coupledwith a first Cache Register located a first one of the first pluralityof Groups; wherein each row of N GBL-divided devices is gated by one offirst control signals, each row of N Segment-divided devices is gated byone of second control signals, each row of N Segment-select devices iscontrolled by one of third control signals, each row of N prechargepull-down devices is controlled by one of fourth control signals,multiple Pages with respective multiple WLs and all GBLs across thearray can be selected on one-page-per-block basis from multipledispersed Blocks in multiple different Sub-segments of one or moreSegments of one or more Groups for at least partially performingsimultaneous Program, Program-Verify, and Read operations.
 14. TheHiNAND flash memory array of claim 13 wherein each Group-divided device,each Segment-divided device, and each Segment-select device, and eachprecharge pull-down device are substantially a same type transistor asan 1-poly NMOS low-voltage (LV) transistor operating under a low-voltageVdd precharge scheme.
 15. The HiNAND flash memory array of claim 13wherein each Group-divided device, each Segment-divided device, and eachSegment-select device, and each precharge pull-down device aresubstantially a same type transistor as an 1-poly NMOSmedium-high-voltage (MHV) transistor operating under a MHV V_(inhibit)˜7V precharge scheme.
 16. The HiNAND flash memory array of claim 13wherein each NAND memory cell is configured to store 2-state SLC, or4-state MLC, or 8-state TLC, or 16-state XLC, or even 256-state analogvalues.
 17. The HiNAND flash memory array of claim 15 wherein eachprecharge-power line associated with each Sub-Segment in a Segment iscommonly connected to a metal line coupled to a voltage decoder forprecharging all or partial N broken-LBLs of the selected Sub-segment ofa Segment simultaneously to a voltage level of a low-voltage Vdd up tomedium-high-voltage V_(inhibit) of ˜7V or discharging to a designatedvoltage level below the precharged voltage level.
 18. The HiNAND flashmemory array of claim 13 wherein multiple precharge-power linesrespectively associated with multiple Sub-segments from multipleSegments of one or more Groups are configured to perform a simultaneousprecharge operation independently by setting corresponding first controlsignals, corresponding second control signals, corresponding thirdcontrol signals, and corresponding fourth control signals topredetermined voltages for performing simultaneous multiple-WL andall-BL Read operation on the basis of one Page per one Group.
 19. TheHiNAND flash memory array of claim 13 wherein each broken-LBL comprisesa metal line parasitic capacitor unit configured to be a dynamic cacheregister for storing temporary program page data during simultaneousmultiple-WL and all-BL Program operation.
 20. The HiNAND flash memoryarray of claim 13 wherein multiple broken-LBL metal line parasiticcapacitor units associated with multiple dispersed Sub-segments in oneor more Segments in one or more Groups are configured to be prechargedsimultaneously to a predetermined voltage above a system voltage Vdd upto 7V for performing multiple-WL All-BL simultaneous Program,Program-Verify, and Read operations rather than charging through a fulllength of the GBL from the page buffer.
 21. The HiNAND flash memoryarray of claim 13 wherein multiple broken-LBL metal line parasiticcapacitor units associated with multiple dispersed Blocks in differentSub-segments of one or more Segments of one or more Groups areconfigured to independently latch and trap a LV system-operation voltageVdd for program-inhibit and a Vss voltage or a voltage less than Vdd-Vtfor program by directly coupling via the N GBLs from the page bufferwith one WL page data pattern of Vdd for program-inhibit and Vss or avoltage less than Vdd-Vt for program, wherein Vt is a threshold voltageof the precharge pull-down device, for executing a simultaneous All-GBLProgram operation based on a self-boosting-program-inhibit scheme. 22.The HiNAND flash memory array of claim 13 wherein multiple broken-LBLmetal line parasitic capacitor units associated with multiple dispersedBlocks in different Segments of one or more Groups are configured toindependently latch and trap a V_(inhibit) voltage above Vdd up to about7V for program-inhibit and Vss voltage or a voltage less than Vdd-Vt forprogram by precharging each of N broken-LBLs to the V_(inhibit) voltagefrom the precharge-power line for each selected Sub-segment, andcoupling via the N GBLs from the page buffer with a WL page data patternof Vdd for program-inhibit and Vss or a voltage less than Vdd-Vt forprogram, for executing a simultaneous All-GBL Program operation onmultiple selected Pages respectively in the multiple dispersed Blocksbased on the corresponding one WL page data pattern using anon-self-boosting-program-inhibit scheme.
 23. The HiNAND flash memoryarray of claim 13 comprising a 3D flash array structure with each Stringof memory cells being stacked in a third direction in a straightvertical-channel configuration, or U-shaped vertical-channelconfiguration, or vertical-gate lateral-channel configuration, the thirddirection being perpendicular to both the first direction and the seconddirection, wherein each Group-divided device, each Segment-divideddevice, each pull-down device, each first String-select device, and eachsecond String-select device associated with a vertical-channel 3D NANDString configuration is selected from a one-transistor device of a sametype NMOS 1-poly transistor, a two-transistor device having two NMOS1-poly transistors with a common gate, and a three-transistor devicehaving two NMOS 1-poly transistors with a common gate plus a third NMOS2-poly transistor.
 24. The HiNAND flash memory array of claim 23 whereineach Group-divided device, each Segment-divided device, each pull-downdevice, each second String-select device associated with a n-layervertical-gate 3D NAND String configuration is a n-transistor devicehaving n NMOS 1-poly MHV transistors connected in parallel where n isnumber of cell layers of the vertical-gate 3D NAND String configurationin the third direction.
 25. The HiNAND flash memory array of claim 23wherein one or more dispersed Pages from K Blocks in different Segmentsof one or more Groups of the 3D flash array structure are configured toflexibly subject to a simultaneous Erase operation by at least settingall first control signals, all second control signals, all third controlsignals, and corresponding precharge-power line to Vdd voltage andturning on both the first String-select device and the secondString-select device corresponding to each selected Block, then rampingthose signals from the Vdd to a Vers voltage of 20V to use agate-induced drain leakage (GIDL) scheme to induce hot-hole to erasetrapped electrons in each memory cell of the whole corresponding Page,wherein K is selected from 16, 32, 64, or any integer number.